Speaker 1: Okay, there we go, there we go. All right, Welcome
to another episode of the Crime Page About It Doesn't podcast.
Today today we're here with my friend, Professor Emeritus Jim
moss Seth and plant anatomus and cactus practologist and fucking
you just do it. Man. You like specializing in cacti,
but like the nitty gritty stuff, the cell walls, the cells,
the different types of tissues, the which is very good
to have this conversation for me now now that I've
been teaching all this stuff. So, oh Jim, how are
you doing good? Yeah? Man, So we were just we
were just started looking at Ariocarpus flowering and beautiful landscape
that hasn't been tarnished or poached yet on a little
private conservation property here in West Texas. So anyway, so yeah, man,
I wanted to, uh, I guess where to start? You know,
I just taught well this is I guess anyone listening
to if you the last podcast episode I taught this
stuff was basically a lecture on there's a brief lecture
on the different types of tissues epidermal tissue, ground tissue,
vascuar tissue, and then you know, within ground tissue. You've
got Prankma, colin kamma, sclare incoma. You're kind of in
a you know, respectively from softer to hard to harder.
Sclaring come as the hardest, Colin come as kind of intermediate.
Priankama is softest. But there's you know, whole definitions that
go with each of those tissue types. And so I
suggest listening to that if if this stuff throws you off.
But I will be trying to you know, intersperse some
crash course, you know, sentences in between the conversation that
we have. So let's just start talking. I mean, let's
just get to it. I guess what I wanted to
ask you about initially, Well, there's a lot of things,
but that that tissue in aerocarpus that's so hard that
I always assumed it just was cutical the waxi layer
exuded by the epidermist. But it's too thick to be
cutical does have a really thick cuticle, but that's probably
epidermis and hypodermis too.
Speaker 2: You were saying, yes, you almost all the cacti, Well,
all cacti I have an epidermis on their young body
where they don't have bark and almost all cact i
have a several layers of hypodermis blow the epidermis, and
the hypodermis always have thick walls, so it's always tougher
than the epidermis. So when you can kind of peel
a thick layer off of an opuntia or a barrel
cactus or something like that, you're not getting just the epidermis,
and you're not getting just the cuticle. You're getting hypodermis.
You're getting two or three or four layers of hypodermis,
one layer of epidermis and cutical and wax and stuff
like that. It's going to be mostly the hypodermis.
Speaker 1: And but hypodermis is still I mean it's still epidermal tissue.
Speaker 2: No, it's not.
Speaker 1: What is it classified as or is it parankamar or
kala kamar? What would you call it?
Speaker 2: Epidermis? The epidermis and plants has a really nice developmental definition.
The the up in the shoot apical marrastem, the outermost
layer of cells can only divide with cell walls that
are perpendicular to the to the surface of the marrowstem,
so that means both new daughter cells are laying in
the same plane, there's still the outermost layers of cells.
If if they if an epidermic cell divided in a
with a wall that's parallel to the surface of the
of this to the skin of the skin, then you
have an outer cell and an inner cell. Don't do that,
so you only divide with that perpendicular wall. So what
the epidermis of a plant does is it is a
single layer that grows as a single layer, a sheet
that just gets bigger and bigger and bigger.
Speaker 1: So you can say still created in the appical marasteme,
which you know, it's like the appical marastime on like
a pay odior and aerocarpus is in the center of
the plant. Yes, that's the only spot where well it's
not the only spot where new cell growth is occurring,
because cacti have secondary growth as well. They've got a
vascular cambium.
Speaker 2: Yes, and you also have the growth of the spines
and growth of the tubercles and long things like lutenbergia
or there's long memalarium, lounge amandma and stuff like that.
But the big deal is that with so with the
epidermis coming from this one layer of cells in the
in the marristem. And then and then having having only
divisions by these perpendicular walls, you're growing as just one
single sheet. So if you can imagine this being this
tabletop being covered by a sheet of cells one cell
layer thick, and every cell can only divide so that
both daughter cells are now laying in this sheet, the
sheet just gets bigger and bigger and bigger and bigger,
but never thicker and thicker and thicker. Okay, So that
gives us a really good definition of epidermis and cacti.
So that on the surface of a leaf, those epiderma
cells have come from that one single layer of the
shootoptical marrastem. And and so so when we're talking about
an epidermis and a hypodermis with layers below the epidermis,
those those layers below the epidermis have not come from
that one single shoot epical marrastem layer, so they have
a different developmental origin.
Speaker 1: They've still come from the shoot apical marius them, but
from a but.
Speaker 2: From a deeper layers. So the fact that so a
really interesting way of thinking about it. Imagine a imagine
a fertilized egg and plants, So the sperm cells just
cheesed with eggs. You've got this one single celled zygoat.
Speaker 1: In animals, you mean in plants too, Okay, yeah, yeah.
Speaker 2: So this single cells zygoat the device and have to
get two cells divisa, those two divide and have to
get four cells and then a cells. And very often
when in plant embryos, when you go from the eight
cell stage to the sixteen cell stage, you're all the
cells divide by a curved walls that are parallel to
the surface of that zygote. And so you get at
that stage, you now get an outer an outer. So yeah,
eight cells divided to get eight outer cells and eight
inner cells. Those eight outer cells are the progenitor for
all the epidermis. So when you look at a when
you look at a big old oak tree or a
pine tree or whatever, and you see the epidermis on
all the every leaf and every flower and everything, all
those singles, all those that single layer of cells covering
all that plant have come from that those outer eight
cells of the sixteen cells stage plant embryo. So at
that very early stage, the epidermis is set off as
being distinct from all the.
Speaker 1: Rest of the they're just copies of those in exact right, Yeah,
but it's all I mean, in an applical mirrors them.
It's all undifferentiated at some point, isn't it. And then
it later. But when you get leaf primoria and then
obviously not in cacti.
Speaker 2: Well no, you do get in you get leaf primoria.
In in cactus, the leaf primori stop developing while they're
still very small. So when in perrescae they developed the
full leaves, right, you know, puncas, they develop in the
smaller leaves that fall off pretty quickly.
Speaker 1: Yeah, those a little cylindrical things, yes.
Speaker 2: And then the regular cacti they develop in the leaves
that are pretty much microscopic by the time they're stopped developing,
where they still have an epidermis, they have a hypodermis,
they have an inner inner cells that are photosynthetic, they
have a xylum they have flown. And there's the strange
thing but these little tiny microscopic leaves of cacti is
they're almost pure asylum. It's just it's just this huge
nodule of xylum with a little bit of green photosynthetic
parankama on one time on the other side, and a
layer of epidermis and hypodermis.
Speaker 1: But and then the spines would be I mean they're
they're technically not leaves, they're bud scales. Bud scales.
Speaker 2: So if you look at a you know, at an
oak bud or the bud of any kind of a tree, well,
it's still.
Speaker 1: Dormant before the leaves have burst out, or the best to.
Speaker 2: Look at them while the leaves are bursting out, and
then the bud scales kind of peel back, and the
bud scales are a little brown scales.
Speaker 1: Yeah, like on buckeyes. They exactly.
Speaker 2: Yeah, so just imagine that those are modified into spines.
Speaker 1: No ship so it's not they're really not technically leaves,
even though they're just called.
Speaker 2: The bud scales are modified leaves.
Speaker 1: Right, So.
Speaker 2: We think of plants as having just three organs, you know, roots, stems,
and leaves. So everything everything that's not modified root or
a modified stem is going to be a modified leaf.
So you get really odd things. That is, it's pretty
easy to see this as a modified leaf. Like the
pictures of picture plants right are modified leaves obviously.
Speaker 1: Or the spines on okatillo, like you can see that's
that's a pettiole. You can see it when that first
new growth, the first leaves on okatillo, it's a that
you could see the spine. It's a pettiole, but it's
got a leaf at the end exactly. And then the
leaf falls off and that's the spine. And then when
then you've but you still got buds at the base
of that spine. So the next season the leaves come
out of that fascicle at the base of the spine.
Speaker 2: Yes, yeah, that's right. Yeah, So so modified leaves are
everywhere in all kinds of crazy shapes and forms.
Speaker 1: You had said you you were mentioning before to the
one thing that cacked I had, Well, there's a couple
of things, but the cortical bundles because they're parentama tissue.
Because most of the MASSI of a cactus is mostly parentama.
We got three tissue trankama. Most of a ca of
a cactus is parentama. It's the low density you know, tissue,
no secondary cell wall, only a primary cell wall. And
most the most common in storage and photosynthesis like those
are the photosynthetic tissue and storage tissue. So since you've
got this and that's what the cortex is yeah right,
So so that epidermal tissue, because that cortex is still thick,
the epidermal tissue having to be supplied with water. Yes,
that you run into a problem there. So that's I
think that's the xylums on the other side of the
cortex from the epidermis.
Speaker 2: Yes, I think it's the easiest to see in in
the second euphobious euphobius that look like cacti. They and
very often you'll see pictures of those were well, this
looks just like a cactus, and they do look just
like a cactus. But if you ever notice that from
really euphobious, they're all is small and they never get
to be great big and giant, like like a big
kind of cactus plotycanthus or a golden barrel anything like that.
Speaker 1: You have a four engines does yeah, the big one.
Speaker 2: But each individual stem is not super thick. It doesn't
have a super cortex.
Speaker 1: Yeah, yeah, you're right.
Speaker 2: But so like we were talking about earlier today, if
think about it, just an ordinary dichot, an ordinary broad
leaf plant was skinny stem, non second stem, and and
an epidermis. So this cortex is maybe an eighth or
sixteenth of an inch thick, and the cortex may have
a cuticle and wax, and it's water proof. It's when
we say waterproof, if we're talking about it's more waterproof
than nothing. But but it's always losing water. The epidermis
is always losing water. So in a in a regular
you die caught, that's not in a desert. Then then
the water is coming up through the island zylum through
the that ring of escuar bundles in the very center
of the stem, and the water for the epidermis can
and for the cortex, it just kind of leaks out
the xylum into the cortex, diffuses across the cortex, plasm
through monit through the wet walls, So all these cortex
cells have wet walls. And then it gets to the epidermis.
And and even though the epidermis is losing water to
the to the air, it can be supplied with water
from the xylum by by passing through this thin cortex.
Speaker 1: Because it doesn't have this, yeah, this thick ass cortex.
Speaker 2: So now imagine, imagine you've got a mutation that causes
the cortex to be twice as thick. Well, that's really
going to slow down the movement of water through it.
So as long as that epidermis, which is now been
pushed farther away from the islum, as long as that
epidermis is not in a very dry area, then it's okay.
It's it's not losing water too rapidly, and our movement
of water through this now thicker cortex is slower, but
it's fast enough to keep that epidermis alive. Okay. Now,
let's have another mutation that moves the mikes, the cortex
thicker and pushes the epidermis farther from the islum. So
the epidermis is still losing its water and it's still
hopefully getting water through the cortex from the islum. But
at some point you can see where you're gonna have
Every time you make the cortex thicker, the movement of
the diffusion of water through that is slower.
Speaker 1: Right, it's slowing it down. But the benefit of having
that cortex so thick because it now you've got all
the storage tissue.
Speaker 2: Yeah right, yeah, But you can still imagine at some
point the cortex is so thick and diffusion through the
cortex is so slow that now the epidom missus in
danger that that the epidemics is losing water and at
some point where where it cannot get water from the
from the dilum through the cortex fast enough.
Speaker 1: You're gonna have to evolve some new tubes. You're going
to have to evolve some new plumbing, right.
Speaker 2: And so that's and that's the that is the magic
feature in the cacti, in.
Speaker 1: The the cortical bundles, the.
Speaker 2: Cortical bundles that they have, and they it could be
that they're modified leaf traces that leaf. You know, you
have vescar bundles that run from the from that central
cylinder of escer bundles out to the leaves and the buds,
and it could be that those started to branch and
just just ramify and be a network out in the cortex.
And and once that happened, and that was just that
was just it has all kinds of benefits.
Speaker 1: Now you can get super thick, the cortex can be, Yeah,
it can be. Now you can get biz nagas and yeah,
it kind of cracked Plady of Canthus and all these
other giants.
Speaker 2: The cortex can be really thick and and you're not
moving water to the epidermis by means of diffusion. Now
you're moving water from the inner set of vascar bundles
out to the epidermis by means of these.
Speaker 1: Cortical bundles, tubes you've got.
Speaker 2: You've got tracheads or vessels.
Speaker 1: And is that what is that what cortical bundles. I mean,
Are they're literally tracheads or vessels or are.
Speaker 2: They No, they have there's there's a both xylum and flowing.
Speaker 1: Oh my god, but they're later they're not.
Speaker 2: They're running, Yes, they're running. They're running more or less
not straight out. It's forming a network. Think think of
it like the network and leaf die caught leaf.
Speaker 1: Yeah.
Speaker 2: So it's a three dimensional network that's running out up
and down and ready outward through the through the cortex.
So even if you'd involved to have a cortex adius
ten feet thick and your epidermis is away out there, Yeah,
as long as the xylum in the center of your
plant has water, it's getting water from the roots, you
can conduct that water out to the epidermist and keep
the epidermis alive.
Speaker 1: So that makes me want to think, That makes me
want to ask you about like when people graft like you,
some of these people graf the cactus nerds grafted or
even like I've been grafting stuff like some of the
native cacti in South Texas, like a kind of serious
Postsel Garrie, because I want to create a bunch and
then you know, have cuttings to give people to re
establish them native plant cards and stuff. You graph that thing.
It grows ten times as fast, twenty times as fast.
But what are you doing when you're grafting that? Because
you're the ring right in cacti being a uticut there,
the vasculature is a ring in the stem with asylum
on the inside and the flow them on the aup correct,
So what are you doing when you're grafting? Because I
like it kind of serious Postel Gray. I'm not it's
a really tall, skinny cactus. Then I'll graft it to
like myrtillo cactus. And I learned that I'm not putting
it directly vertically because it's just this tiny pencil thick thing.
I'll cut it in half vertically and then lay it
horizontally on top of them martillity caractus. What's going on there?
How is the vascular because the vasculature has to meet
up right.
Speaker 2: Yes, it does, and you know sometimes it doesn't, and
that when it doesn't, then then your graft music okay
for a few months, and then the then the sign
just falls off. It shows up and falls off because
you never have established a vascular connection.
Speaker 1: But maybe you were just tied into some cortical bundles
and that's why it didn't die immediately. But you're not
into the true zion, right.
Speaker 2: So what happens in in a successful graft is the
cutting has caused a wound response, and so the cells
that are near that, near the cut cells, they start
to start to divide as if they were going to
form a scar tissue over the surface, but now they're
they're inside this graft union there with a nice wet
stock on the top and a nice wet sign on
the bottom, vice versa. And so they divide, but they
don't then turn into scar tissues. They don't die because
they don't die. Yeah, they did.
Speaker 1: It's glaring kama or what is it exactly?
Speaker 2: It's more kind of kind of a bark.
Speaker 1: Yeah, But in that I mean, at the if you
look at the cutting of say that the stock, you've
got the pith and the cortex, and that's all the
parent command and then you've got the vasculature, which is
a completely different kind of tissue. But basically, what you're
trying to do is mix the vascular tick mix, have
the vascular tissue of the stock mate up with the
vascular tissue of the scion.
Speaker 2: Trying to get there. You're trying to get the vascular
cambium of the two to be as close together as possible.
Speaker 1: And where is the vascular cambium that would be more
towards the outside.
Speaker 2: Yes, close to the flow. Between the flow and the xylum.
Speaker 1: The ring you see is going to be xylum and flowing.
Speaker 2: The ring you see is going to be mostly xylum,
just a little bit of flowing and that. And that's
because you know, the xylum, the xylem just persists and
just a cumulus as wood with the flow. When foam stops,
When floam stops conducting, it collapses.
Speaker 1: Well, flows alive at maturity, and xylon is dead at
maturity as well. Right for the most part, are there.
Speaker 2: For the most part?
Speaker 1: Yeah?
Speaker 2: Okay, yeah, but but the floam, this the siep tubes
and flow usually only conduct for anywhere from a few
weeks to maybe two or three years. And then when
they stop conducting, they usually collapse and then in everyplaced
by Yeah, the cambium is concreting new floam if it's
got a cambium.
Speaker 1: But like in monoconts, that's totally different thing. Secondary growth.
Speaker 2: Yeah, so you can't can you graph monocots.
Speaker 1: No, we're going to get that. We're going to get
the Monocst's going to be a long conversation.
Speaker 2: So you've gotta grating. You're grapping woody plants, you're grapping
die coots or conifers, and and so you you try
to get those the two cambia lined up as much
as possible, and they're creating cells. Basically, it's kind of
a wound, kind of a wound callous and apparently there's
some there's a factor that comes from the from the
cambium of one and the fact that comes from the
cambium of two, and so you have this diffusion field
and the new xyland flow can can differentiate towards the
new cambium of the one, the new cambium the cameum
with the other one, and so we get this this
graft union form. You get continuous asylum from the stock
up into the scion continuous flow. So if it.
Speaker 1: Works, so you can't I didn't realize that before. You
can't graft monocots like wow, I don't, Yeah, because it's
totally different. Instead of it being a ring, they're just
kind of scattered at a.
Speaker 2: Curtain and yeah and yeah, and they're usually not going
to form a scar tissue. They mostly just die and
you get maybe you get one layer of quirky cells
at the surface, but you're not going to get a
real proliferation of cells and monocots.
Speaker 1: I don't know why I didn't realize that.
Speaker 2: But in the cortical bundles. There's a there's a mistletoe
in in southern Peru that called Lagaria that attacks a
big columnar cactus and and most yes Ligaria l I,
G A, R A, and so it most cacti are
protected from mistletoes because the mistletoe seed will land on
the surface and then it's got to get some cells,
got to get some house storyum root tip into the
into the host and then get that root tip into
the flow and start you know, getting nutrients. But the
characters have big thick cortex that the poor parasite is
in there and there's just cortex which is just water,
just water balon, yeah, and nothing to eat more watermelon,
more model watermelon. And finally after the poor little say
ordinary mistletoe, this it's its root has grown through this cortex.
Finally the seed just runs out of energy and it dies.
So most cacti I pretty well protected from mistletoe just
by being sold.
Speaker 1: It's got to tap into the xylum and flown exactly.
Speaker 2: But lagaria does this crazy thing. It taps into the
cortical bundles.
Speaker 1: That sure, is that what trist rex does too, No.
Speaker 2: Tristrix, that's a whole different story.
Speaker 1: Okay, let's think tristris last conversation.
Speaker 2: So with with lagaria, it's it's a historium. Instead of
searching for the those vascular bundles in the very center
of this stem it, it finds a cortical bundle which
has island flown and it's pretty weak and so you
wouldn't expect it to have very much conduction capacity for
this mistletoe. But the lagaria stimulates the cactus to then
have this this cortical bundles to start growing and getting thicker,
as if it were like say, uh, the basket supply
to a branch.
Speaker 1: How is it doing that? It's how is it manipulating
the cactus into.
Speaker 2: I would guess supplaying with hormones, probably xylon, probably with
oxen or sodokin and then but so it's like, okay,
the parasite went just making this, causing the host cactus
to start making all this xylum which should be feeding
the parasite. But wonderful thing about evolition Xylum secondary islum
is conducting vessels and supporting fibers, and the fibers are
just you know, thick walled.
Speaker 1: Tough fibers, aren't doing any conducting, they're.
Speaker 2: Not doing any clan struct cacti that can cacti. The
fibers stay alive, but they're thick walled, they can't conduct,
they have almost no nutrients in them. And so so
the cactus has been tricked into making wood by the lagaria.
But the cactus responds by making a wood that is
almost purely fibers. It's not not conducting, So so the
poor lagaria is pretty much just screwed. Now. Apparently, every
once in a while it's able to get enough get.
Speaker 1: Enough, so lagaria doesn't normally infect cact diets.
Speaker 2: No it does.
Speaker 1: It's going for other things and then ends up on
kacti or what.
Speaker 2: No, it's I think it's pretty specific, this lagaria, but
run out of I mean, well, no, it is somehow
Apparently every once in a while it works and it
tricks the cactus and the cactus does respond properly, and
so you get and then so you do get this
these cortical bundles growing into a big, nice, good supply
that that does keep the lagary growing. Then the lagary
g to be a great, big bush. It's huge, and
apparently and then the top of the cactus above this
point of infection dies. So you're driving along and southern
Peru and you see this cactus with a bush on
top of it, and you go, what the hell is that? Yeah,
and it's so you can't miss it. It's it's you know,
with other plants you kind of have to search and
search and search to find a missiletoe, and this is like,
oh no, it's this huge bush sitting on top of
a cactus.
Speaker 1: Yeah. There's a paper I'm trying to look at right now,
and I see host response and endophyte structure written by you.
A missiletoe that attacks cacti like Garia cunifolia. Yeah, Choreo
Cactus brevist stylista. I remember seeing that one. So that's cool.
Speaker 2: So this is the only one that we know where
the missiletoe attacks is able to survive by attacking cortical
bundles and the tristricks ay phyllis that you were talking
about before that attacks, uh, the treka serius in Chili.
What it does is a totally bizarre biology that the
root tip the houstorium of the parasite seedling. The root
tip presses against the cactus epidermis that has cuticle and
wax and stuff like that, and layer after layer of
thick walled hypoderma cells and like any missiles, so then
the storiam tip just presses against the cactus surface and
kind of spreads out and it glues itself. And then
and then once it's really glued to the cactus, it
spreads and contracts, and this contraction rips the epidermis off
of the cactus and it it basically sucks the sucks
the the cactus cuticle and wax and stuff like that
up into the root tip of the parasite. You've gotta
you have to see the pictures in the paper, so
you can imagine a root tip down here, and you
take a longitudinal section and there in the middle of
the of the parasite's root you have the pieces of
the cactuses cuticle got it ripped off, and then and
then the parasite now is laying right against this naked hypodermis,
no cuticle, no wax, no nothing to protect that poor cactus.
And the tristrix then presses against the hypodermis and you
have all wherever there was a stoma in the epidermis
with your two guard cells below that. You have to
have a hole in the hypoderma so that carbon dioxi
I can get once it gets through the stoma, so
model poor you can get through the hypodermis and into
the cactus cortex. Well with the ligeria. What the tristrix
does is it presses against those holes, and some of
its root cells then squeeze through the holes and get
into the The wholes are subst model chambers you sendto
the charactus cortex and then they start to proliferate these skinny, skinny,
skinny parasite cells and then start to divide and divide.
Speaker 1: It just using the endosperm from the original seed, or
is it.
Speaker 2: Well, at this point, now they're probably starting to draw
nutrients from the from the cactus cortex. Now no I
talked to earlier that well, on regular missiletow they can't
get enough nutrient from the cactus cortex because it's just
so watery and so so poor and starch. But now
we're not trying to feed a whole seeding, We're just
feeding one or two cells of the parasite so creepy,
So the parasite cells start to kind of proliferate almost
like a like a little callous little nodule, and the
seed dies at that point. Then the then the tristrics
seed dies and the parasite exists as nothing except this
little nodule of cells inside the cactus cortex. And so
then they just start to make these long, skinny cells
that then squeeze in between the cactus cells and start
invading the cactus cortex kind of like a fungus my
celium would do, and.
Speaker 1: So fucking insane.
Speaker 2: So at this point, you've got this, You've got this
mistletoe which is in you a diecot seed plant that
its body is nothing except a few little prank mysel exactly.
So this and so it can grow. We have no
idea how many months or years it takes, but it grows,
and it grows up up the cortex and down the
cortex and in and it it doesn't really look like
it's well. It might there might be chemical cues for
to find where the where the sugary floam is, but
it kind of seems like it's just wandering around at random.
But eventually some of the cells make it to the flow,
and then they start to really proliferate and they become thicker,
but they still just stay as these strands of parenama,
and at some point they might form one cell of asylum,
a cell of flow, not.
Speaker 1: A strand of just single cells. Yes, it's literally behaving
because you look at the host plants in Chile, like
you Lickna and the Tricho series, and they don't look sick.
But they've got the tristrics flowers bursting out of the top,
but it doesn't look like it's actually killing the tree.
Like if you look at an oak tree that's got
mistletoe on it, sometimes you can see the oak tree
is stressed out, but none of the cact i seem
too stressed out. Is that because it's it's so so thin,
like it's this.
Speaker 2: Yeah, that's a good question that it could be that.
And of course to be a really well adapted parasite,
you should not kill your host. Yeah, And it could
be that the tristrix is just a really well adapted
parasite that it's it's not vigor enough, vigorous enough to
really hurt the host. So the host keeps growing so
the parasite can keep on him. The case, the host
keeps growing upward and the parasite can keep growing upward.
Speaker 1: Living in between the cells for the most part exactly.
Speaker 2: But how does it.
Speaker 1: It's kind of happen to the cells at some point,
right nutrients.
Speaker 2: And but when you look at it with the microscope,
it looks like the the host the cactus has no
clue that the cell that the hosts cell right next
right next to.
Speaker 1: The parasite, no defense response.
Speaker 2: No obvious defense response whatsoever. They just they just both
look happy as they can be.
Speaker 1: And so you see that at a cellular level too.
Speaker 2: Yeah, And so then so then the tristrict can then,
like I said, we have no idea how long it
grows with no body other than just this frank or
useless one or two useless zyum cells, one or two
useless flow them cells. Test that by by taking a
taking a coast cactus that has just a little tiny
bit of obvious parasite on the outside of it, and
then then we take samples up, up and down and
on the sides and on the opposite side, and make
microscope slides and look for are there any parasite cells
here or is this parasite free? And so we can
go a meter above and down below and all around
and you'll find parasite cells. So the parasite looks like
it's just growing all through.
Speaker 1: Throughout the cactus, but not only existing. Is these very
thin strands between the cells.
Speaker 2: Get yeahs it finally gets from the zynom a flow
and then the strands starts to thicken. They get they
have longitudin each cell has a lunch ofitudinal division. So
it's now two cells thick for cells thick. And then
we'll make like I said, are useless one or two
xium cells and flow them cells. Then at some point
the strands will get to be pretty thick, but pretty
thick still microscopic, and at some point they will start
to grow outwards towards the surface of the cactus. And
how they is that just random or can they detect? Well,
there's there's sort of sort of some light out there,
or there's more oxygen out there or something. But they
grow towards the surface, and then there's still stuck below
all these layers of hypodermis and epidermis, and they start
to form a nodule again. And then inside this nodule
you get some cells start to divide really fast and
form an adventitious bud, an adventitious flower bud. And then
it pushes out and breaks breaks the cactus epidermis and
hypodermis breaks it open. And then this this tristrics flower,
the parasite flower, emerges from the cactus.
Speaker 1: They come out the aerials, they do.
Speaker 2: Yeah, so the areals might be a soft spot where
the there was a flower, and so there's just there's
abscisions on that's soft. But yeah, and so then the
and then the cycles complete. But then but then even
after that's happened, the parasite, the parasite inside the host
cactus still continues to grow and grow and and you've seen.
You've seen sometimes the mistletoe on the outside, after flowering
and fruiting.
Speaker 1: Will just die, but.
Speaker 2: That same plant on the inside is still healthy and
still growing. You I can imagine like like when when
bulbs die back during winter, so you lose all that
outer part, but the bulb part still stays alive. So
the same thing is happening with this parasite in this cactus.
The out of parts die and the inner parts stay alive,
maybe dormant, maybe still growing.
Speaker 1: It's so weird. Yeah, it was anybody else studying it.
Speaker 2: Its anatomy I don't know that I know of, and
so I've just written like one or two papers on it.
So it's something that anybody should study.
Speaker 1: Did you would you? You weren't able to get material
back to U T. Austin. Were you were you doing
at the university down there?
Speaker 2: And yeah, at the Catholic University in Santiago.
Speaker 1: Yeah, that's so cool. If you hadn't done that work,
nobody would have known how fucking weird that plants.
Speaker 2: Yeah, So I like to think of it as ask
how much can a plant lose and still be a plant?
So this so after this, after the parasite seed gets
his few cells into the cactus, and this parasite seed dies.
Then its body is just these few little prankama cells.
So it has no it has no stem, no leaf,
no root, no epidermis, no hypodermis, no flowers.
Speaker 1: No, it's just it's just p cells living inside the host.
That's insane, yea.
Speaker 2: And of course it's living inside of a food source.
So think of it. I think it was the tapeworm.
So tapeworm gets inside of us. It doesn't need to
have arms or legs or anything like that. All it
just needs to do is be able to absorb material
out of our gut and reproduce.
Speaker 1: Man, do you know, I wonder what's the case with
pilos styles. Has anyone dissected like Dahlia for testins wood
or any of the other host plants and seeing what's
going on with.
Speaker 2: That, Yes, there's a nice there's there are several nice
papers on Pilostylis, and it's pretty similar that it gets
some parankuma into the Dahlia xylum and then that and
then after that, the pilostyles seed dies and the pilot
stati's body and I just consists of a few cells
in this in the host plant body and grows up
and down well, I don't know if it grows down
grows up, and as long as the host is alive
and healthy, then every year you get more and more
host shoot and so the pilot starts presumably can grow up.
There's I know of two or three papers. One is
in nineteen fifty seven, I can't remember the author, and
then there's been a more recent one with really beautiful,
very very thin sections that that could trace where the
cells are withinside the host's body.
Speaker 1: But the seed, I mean kind of like in restorates.
The seed is just kind of a spaceship to get
a couple of cells into the host and then anymore exactly,
it's like a little shuttle just to get it.
Speaker 2: Yeah, so then the idea of making a whole seed
and then throwing it all away is is pretty bizarre.
Speaker 1: But why does does well? I guess I've only seen
it on Dahlia for Testants. I've never seen pilos stylies.
I'm like Sorro feminists, the smoke tree in i Mohave Desert,
but but it liked the one in Daily in the
Daily for Testants, I've seen. It's always the flowers always
erupt out of the lower extremities of the shrub, which
is weird.
Speaker 2: That's what I've seen to you.
Speaker 1: They smell really good. To have you smelled them afore?
Speaker 2: I can't.
Speaker 1: I haven't.
Speaker 2: I've tried. I can smell them.
Speaker 1: God, they smelled so good. They were going off and
these butterflies were hitting them. They were pollinated by butterflies.
They got a really nice photo of a butterfly. Second,
I've been that.
Speaker 2: I look at the same population that you've looked at,
and I've driven up and down that road at a
time when they were not in bloom and and I
couldn't see daily I couldn't see I saw a lot
about the daily plants, but I didn't see any with
the pilot studies on them. So I think it might
be just a few as in that one small area.
Speaker 1: I wonder what the fruit looks like.
Speaker 2: I have no idea how.
Speaker 1: It's this spersed. There's that really tristrics. There's a really
good David Attenborough footage you can watch it on YouTube
of the bird shitting on a shitting out of tristric
seed on a cacas. They they did a really great job,
it's in depth.
Speaker 2: But well, the tristric seed has another sweet so it's
a one seeded pseudo fruit, one pseudo seeded fruit. So
it looks like a little tiny grape with a kind
of a translucent skin, and you can see the seed
inside and the the the embryo is bright green, emerald green,
just packed full of chlorophylls. So no odd thing for
a hollow parasite. But and this the little fruits will
stay healthy for a long long time. But if you
then just take a razor blade and just scar that
fruit wall, probably what you're doing is letting out carbon dioxide,
so the CO two that the respiration is built up
inside is released. Then the embryo immediately, like within minutes,
starts to get longer. And you can see this green,
this green radical start to emerge. If you if you
take the fruit and you just cut off the end
where the radical is, then within minutes the radical pushes out.
And if you if you're just letting it sit there
on the table, the radical pushes out and then turns down.
Speaker 1: And within a few minutes.
Speaker 2: Within a few minutes, yeah, and so it's like, so
I've always wondered if if you is that radical turning
downward or as it turning towards the dark tabletop, you know,
turning away from light. But that would help find the
cactus body if it's growing towards something dark. If it's
just growing down then if the seed dands on a
on a spine, then the radical would just grow downward,
which would be useless. So my guess is that probably
grows towards darkness or or maybe away from light and
finds the cactus body that way. But it's but it's
fast and and the radical can get to be long
two inches easily. Wow, you'll see them on rocks. You'll
see the the the tristrics fruits have germinator fallen on
rocks and germinate on rocks and big old long radicals.
That of course then this everything dies.
Speaker 1: But it's just injecting cells into the host.
Speaker 2: Yeah.
Speaker 1: I wonder how easy that would be to grow in cultivation.
I've got a couple of trichos serious Chili Wentz's seedlings.
I just need to get seed of trystrics. Now it
would be really curious.
Speaker 2: To Yeah, it'd be. And there's a report that that
Tristrix has been found on eight different species of cactus
in Chile, and I've only seen it on the Trekoserris chiliensis.
Speaker 1: I've seen on Eulycnia, and I saw it on Michellio Pontia,
that o pontioid, but it wasn't doing It wasn't It
didn't seem like it was thriving. And the cactus looks fine,
of course, so it can probably infect them, but it doesn't.
It's mostly on Eulycnia.
Speaker 2: And Yeah, that's an interesting thing about parasites is some
of the viscum parasites can infect various species of euphobia,
but they don't do well, and they don't seem like
they've It looks like the hosts are not really susceptible.
Speaker 1: Hid Nora africana. Have you seen that before?
Speaker 2: Yeah?
Speaker 1: God? What is Has anyone looked at that? Because that
infects some of those giant poison bush euphorbias.
Speaker 2: Yes, I don't know. I haven't seen papers, but I
can't imagine nobody's look at it.
Speaker 1: Pro Panky the other weird one that I guess they're in,
aristolochiac Prosa panky is Hignoria is too, I think their
sister genia.
Speaker 2: Yeah, Prosa Panky is in Argentina.
Speaker 1: What is it in fact there or what is it?
What's the host plant?
Speaker 2: I don't know. I saw it with Roberto Kisling one time.
Speaker 1: I've only seen specimens. God, that's so great. You got
to see it. And ye.
Speaker 2: That all the steaments united, the one great big anthro
type thing. Okay, let's but there's so I said that,
it's hard to imagine nobody's looked at it. But but
it's just amazing how many bizarre things that nobody looks at.
So so the tristicks on, the trichosaurs and Chile is
right there on on next to the highway, and everybody
drives by it, and nobody had looked at it until
I came on.
Speaker 1: Man, people take everything for credit. They just.
Speaker 2: Well, it's also you know, you look at it and
there's just nothing to compare to you. So it's like,
you know, you find new a new composite flowering, Well
you can compare to all the other thousands of compositis.
Well it's different this way, it's different that way. But
you find a missletone that is totally bizarre, where do
you even start? So you have to be kind of
like kind of naive and think, well, I'll just I'll
just explain it I see, and then come to find
out that's what it is, and nobody's ever looked.
Speaker 1: I wonder what's going on with some of the micoheterotrophes,
like the plants that parasitize fungky like Monotropa uniflora like.
Looking at the seeds of those, they're tiny, there's no
there's barely any endosperm. They literally just have to fall
in their dust. They literally have to fall on the
ground and hope that they land on close close fungus. Yeah,
I would suppose. I don't know that's but that's true.
Speaker 2: That's true of almost every kind of reproduction that you have.
You produce a gigantic number of seeds or spores, and
then almost all of them don't make it. So think
of a think of a stable population of say let's
use oaks. Since since we're in Texas, you've got a
stable population of a thousand oaks in this area, and
over the years or the lifetime of those thousand oaks,
they're going to make zillions of seeds. But how many
seeds have to germinate and survive and make it to
where they can reproduce only one per plant. If you
have if if some plant is really lucky and I'll
say ten seeds germinate and survive, that it's not a
stable of population anymore. It's growing population. No, you have
ony ten seeds. Yeah, So so we look at it.
Most of the ecosystems of the world, we've got pretty
much table populations. Every one of those plants is succeeded
by only one plant, which.
Speaker 1: Means that so many don't make it. They get eaten
or they.
Speaker 2: Just exactly yeah. Right, So it's it's it's bizarre to think,
but but you know, ideally the one that makes it
is it's a little bit better adapted than all the
ones that don't make it.
Speaker 1: Okay, So moving on to another weird thing about cacti,
and we're just using I mean, that's your specialty. And
it's a great example too, because you have any pesky
leaves to get in the way for the most part.
But root spurs cactus roots have always like enthralled me
because they just you got to figure in some of
these deserts where they grow, the soil too is getting
bone dry. Yeah, like just there's you know, moisture just
it's there to an extent that sure it can go deep,
but you know, most cac roots stay pretty close to
the surface of the soil. Anyway, What what is going
on with cactus roots? I mean, I want to talk
about root spurs as well, but but how can a
cactus roots they embedded in rock. I guess it's not
losing moisture in most cases.
Speaker 2: Yeah, and this is this is something that's not really
been studied very well. So at one point I thought, well,
I'm going to start studying cactus roots because I've been
studying shoots so long. But then all that takes is
trying to dig a cactus route out of out of
solid rock in the hot sun, and you find yourself, well,
I'm going to study something else that's a little bit easier.
So Norman Boke.
Speaker 1: And is that who Epathy Lantho Bogi is named it for?
Speaker 2: Yes, yeah, okay, yeah, and that's an important name.
Speaker 1: He he uh.
Speaker 2: He did research on cacti in the America's Southwest in
the nineteen fifties and sixties, and this beautiful paper just
really really clarified lots of things and really made it
understandable of what's going on in cacti. But for some reason,
somehow he's just not very often sighted. That not people
money know him. But but he was really great. He's
passed away. But but Norman boat Be okay, e's really
an important kind anatomous for cactus studies and things. But
he found an opuntian near El Paso that was growing
in sand and pulls it up and notice that there's
on the roots, there's the little spurs along the roots,
just short, little short, little nubs. And he found that
when it rains, those little nubs can grow out to
be short roots, and they grow out rapidly with just
a maunter of hours, and they have root hairs a matter.
Speaker 1: Of hours, yes, and so they look like little nodules
or what.
Speaker 2: So there basically the preformed roots that just need to
be well, like the radical, like the root in a seed,
it's already formed. It just needs to be hydrated.
Speaker 1: You've got a food reserve there too. I mean to
grow that fast, I don't know.
Speaker 2: I would guess probably, I don't know.
Speaker 1: But within a matter of hours of a rain shooting.
Speaker 2: And they shoot out, put out lots and lots of
root hairs. They don't have a root cap so even
over the apex, they have root hairs and can just
absorb water like crazy, get it back into the.
Speaker 1: Main don't have a root cap. Wow, they can.
Speaker 2: Bring that water back into the main route and then
get it up into the body very very quickly.
Speaker 1: The root cap is like the little helmet that protects
them from wile, especially going if you're going through sand.
Speaker 2: But these are not going to last long, so it
doesn't matter if they get hurt.
Speaker 1: So the root spurs are literally just out there to
cast out, collect water and then die.
Speaker 2: Yeah.
Speaker 1: The roots spurs, yeah wow.
Speaker 2: I would say think of them like the leaves of
okotillo that when there's rain you put them out and
then letting.
Speaker 1: They're just meant to be ephemeral.
Speaker 2: Yeah. Yeah, they're just ephemeral roots. And then but when
they die at their base, a few roots, a few
root cells stay alive and then make a root primoive
and make this make the next little root spur. And
then year after year after year after this happens over
and over and over again, and then you build up
this little spur. Now you can kind of see it.
Speaker 1: Yeah, So that's what the spur is. It's kind of
like layers of those different.
Speaker 2: Yeah, yeah, the remnants of the previous year's stuff. And
so both found this in a puntia or an area,
and then Nigel Taylor has looked for these in a
bunch of other cacti and found them in a lot.
I've looked at looked for them occasionally when I get
a plant and from a nursery, and I very often
see them, but I've never made a real all out
effort enough to say, yeah, they occur in everything.
Speaker 1: God, that's so cool. Though. I knew there was something
weird about because you figure, I mean, when you think
about it, you like, this thing is sitting in like aerocarpus,
it's sitting in limestone, like that's got to get hot
as hell and completely dry, like bone dry. When you're
going for a few months without any rain and whatever.
Speaker 2: It rains, you can't at that point, you can't say, oh,
I better start making a root now, right.
Speaker 1: You've got to have it ready to go. Yeah, so
there was in a few hours, it just shoots out.
And so that's what. So that's the answer to there
that soil or soil conditions is the roots burs.
Speaker 2: Probably, but it but then you think about it, that
In addition to absorbing water and minerals, another thing that
roots do is they secrete side of canons and so
and so the side of canons and to go from
the roots up into the shoots. So what this is
and and of course the shoots are making oxens that
get transported down to the root. And so this is
so you've got this plant, you know, a great big
tree or a little tiny cactus. And how do they
know what's going on with the rest of the body.
You know, we've got blood that circuits around a nerve
nervous system, But how does a shoot know. Oh my gosh,
the roots are happy, the roots have water, the roots
have minerals. I might as well I put out some
relieves because it's my healthy root system is gonna give
me water. So if so, when the roots are happy,
they make cider kinin that goes up from them.
Speaker 1: Just the plant hormone like oxen.
Speaker 2: Yeah, and so it goes up this sudden this hormone
goes up into the stem and says the roots are happy,
go ahead, and then the shoe can become active. And
they're making this hormone that goes down to the roots
and says the shoot's active, so keep growing, keep getting water,
keep getting minerals. In cacti where they can just sit
in a dry soil for months and months and months
and months, are the roots dormant and not making CID
of kinin so they're telling the shoot don't grow, the
soil is dry. I have no cid of kinon so
and then and then do these spur roots when they
grow out, do they give a burst of side of
kind and say, oh, we're happy, go ahead and grow
or or so this's that aspect. So I know a
little bit of the anatomy of these things, but we
don't know anything about the physiology.
Speaker 1: That's crazy to me because those are that's such a
huge I mean, they've just mastered growing in such a
shitty place. I mean just in terms of I love
the desert, but you know what I mean, Yeah, yeah,
I mean it's they shouldn't be there, and then they
figured it out.
Speaker 2: Does this does this biology then carry over to the
epiphetic cacti where you've got they've got roots in the
in the humans and stuff and yeah, in dead litter
in the tree tree canopy.
Speaker 1: Well, I mean you still aren't growing in any soil
maybe some of them there's like there's humans up there,
but you're still can get really dry even and you know,
so you've got.
Speaker 2: Again the only thing to do is look, do these
things have spur roots?
Speaker 1: Or how many cacti have been found that don't have
spur roots?
Speaker 2: Well, that's I mean negative evidence. Negative evidence is always
worse than that just because.
Speaker 1: They're not there, you don't see them, that it can't
produce them.
Speaker 2: Yeah, yeah, and you don't know because nobody's looked, because
nobody's looked carefully enough, or that they don't.
Speaker 1: But I think it's safe to presume that most cacked i,
at least in hot dry areas do this, because that
seems that's a huge benefit. You're having a little root
that can grow, can just take off within a few hours.
Speaker 2: Assumptions. Assumptions will get you into a whole lot of
try Yeah. Well knowing that though, but well, yeah, that
can be your hypothesis. Hypothesis is that probably most cacked
i in hot dry areas have rootspurs So then the
easiest thing to do is go out and look. You
order a cactus from a nursery that's been pretty carefully unpotted,
and the roots are probably pretty undamaged, or you dig
one up from the habitat carefully and roots are undamaged,
and look at them. And and what what Nigel did
is he he got a bunch of cacti and parted
them up until they were happy and growing well, and
then just stopped watering them and let them dry for
a long time. And then after they'd been pretty stressed,
then he watered them and then parted them and looked
and found these little roots spurs all over the place.
Speaker 1: That is that's so fascinating. I had no idea.
Speaker 2: Yeah, it was a super simple experiment, and you don't
need a lot of money, you don't need a lot
of equipment. It's just just doing look maybe with a
hand lenser naked eye.
Speaker 1: Yeah, okay, So root spurs basically are like these precharged
little nodules in cacti that are ready to respond to
rain really quickly and then just send out, send out.
How many other plant families do that? You know there's
something analogous to that.
Speaker 2: Well, well, that's a good question that then I don't
know the answer to. And and one thing that's always
interested me, interested me is what do the roots of
bulbs do. So you've got like around Austin, we've got
we've got oxplit lily that blooms now and then piss
up its leaves in early winter and then goes totally
dormant for months and months and months until the next September.
And what are their roots doing. My guess is that
they've hab sized all the routes that they have no
roots doing.
Speaker 1: It would make sense. Yeah, I just cut them off
because you're going to be losing moisture. I mean, even
though the roots sealed off from the atmosphere, there's still moisture.
Speaker 2: They're in dry soil.
Speaker 1: They've got to be being Yeah, there's moisture, got it,
that's probably going to be pulled out of them.
Speaker 2: Yeah. And onions and their roots are all dead, and
it's not that the farmers cut them off. It's just
the roots die. But on palm trees, their roots, their
roots don't die. And palms are just a giant bulb
they are.
Speaker 1: To explain that you have a dug of a palm seedling,
so oh, yeah, actually, yeah, you're right, I have Yeah, yeah,
it does look kind of like an onion.
Speaker 2: Well, you know, you've got a little tiny palm seed,
and that's the coconut. Most palm seeds are pretty small,
and that seedlings makes us a little short, skinny shoot
that doesn't have enough room for very many adventitious roots.
Speaker 1: So so what.
Speaker 2: Palms do is they go through a period called establishment
growth where they stay where the base of the stem
stays underground, and the thing just gets wider and wider
and wider, but not longer. And you know, making one
or two leaves, it gets wider and wider and water
so it can make more and more adventitious boot but
roots for all these extra vascuar bundles that's making. And
then at some point when it's really wide and has
lots and lots of basket bundles and lots and lots
of adventious roots, then it starts to grow up and
for a while it continues to make more adventurous roots
out into the soil. And in palms especially, you can
see that even after this stem is above the soil level,
they'll still make adventitious routs. Yeah, but they aren't able
to get to the soil, so they die and kick
the bucket.
Speaker 1: And you'll even see on some public the Washingtonians which
get planted weights in which they've got that kind of
flanged base.
Speaker 2: Exactly, so they make all those adventirous roots that are
pushing out, and then you gotta have room for them.
Speaker 1: But so it's wider, but it's not, it's still.
Speaker 2: Not it's seconds lateral as No, it's just lots and
lots of bascular bundles in this, in this monocot cylinder,
that is a bunch of scattered bundles, not a ring
ring like in fact. So so I've wondered about the
roots of most bulbs and monocass like go dormant? Do
the do the roots die? And just think about it.
We can just walk around and look at what a
stem is doing. Oh, the leaves have fallen off. It's winter,
it's dormant. Oh the flowers are coming out in the spring.
The leaves are coming out. But we have no idea
what the roots are doing unless you dig them up.
And and once you dig them up then probably you
can't really bury them again.
Speaker 1: And you don't have a tap root. Of course, it's
fibers all monoconts.
Speaker 2: Yea, what is that? God?
Speaker 1: There's that? This is? This would be a curious thing
to study there's that palm pseudo phoenix. It grows in
the Dominican Republic. It's like a bottle palm. It's oh,
why right, what is going on? That's that's got to
just be parankama.
Speaker 2: I think it is. I think it's parankama that in
between the basket bundles that for some reason, it just
starts to divide again. After it's been sitting there for years,
it starts to divide. Makes this makes the stem wider,
gives it this bottle shape.
Speaker 1: Yes, Phoenix vaniphra here, this guy, what a beautiful it's
it's yeah, it's got that layer of farina on the
outside too. Yeah.
Speaker 2: So Bob, I would guess extra storage cells.
Speaker 1: That are just larger, I mean more and more storage
cells and then yeah, but it's still originally created at
the appical marast.
Speaker 2: Well, you know, you think of parankama as being these
big cells with thin walls. But but there's one thing
to be to have one big cell with thin walls,
or if you have that same volume, you have two
cells that together the same volume and they have thin walls,
that's going to be a little bit stronger, a little
bit tougher than one giant.
Speaker 1: Right, because you've masked for mass, you've got pine, you've
got more cell.
Speaker 2: Walls in there. So I have So when you get
really great big cells like in watermelon, fruit or or
ice plant, the we have those giant crystalline cells on
the surface, they're just so fragile you can't really do
much of anything with them. So it's just better to
have a bunch of smaller cells. Right, there's still pranking,
just thin walls, but that's going to be strong on
a few great big cells.
Speaker 1: You've still got thin walls, right, But because there's so
many more cells, you've got more structure in there. Yeah. Yeah,
what is the I want to talk about innerclorie marastimes
a mono constitute. But before I forget this, I want
to get back to what like when you look at
a choya or some of the cat you get that
criss crossing wood. Oh, what's up with that? What is that? Exactly? Yeah,
it's old xylum tissue, you know.
Speaker 2: Yeah, it's the secondary'sonymous wood.
Speaker 1: It's old water plumbing.
Speaker 2: But well, think about think about something like bamboo is
an easy example. So you bamboo, you've got these nodes
and long, skinny nodes and especially think of think of
a variegated bamboo with the yellow and green stripes, and
the stripes always run perfectly straight up the stem. They
don't run around in circles, they don't run around in spirals,
they just go straight up the stem. Well, in bamboo,
you're the cells that make the Internet is longer are
transverse divisions, and the cells elongate, and the vascar bundles
are doing the same thing. So a vascuar bundle runs
straight up a stem of bamboo.
Speaker 1: And but.
Speaker 2: If that were the only thing, you'd have a vascuar
bundle that starts with the route and then just goes
all the way up to the top. And if something
happens that you're you're in trouble, you know, if the
insect bites to it. So at every place where there's
a node, the bundles come together and and form a neck,
a network that water can be shared in the zion flow,
sugar can be shared in the flow. And if something's damaged,
basket bundles damaged. Here at the next node you can
you can kind of get around it and detur around it.
Speaker 1: It's like having a string of Christmas lights, the old
school ones where if one light went out, the whole
thing goes out. This is the way around that.
Speaker 2: But if you if you interconnect them, you can get
around it. And then and then die coots and you
dye coots. They don't. So when I say you dyecot,
so the word die coot is now out right right
right you I.
Speaker 1: Still explain it just monocot, diecot. But just know there's
some stuff in between. Yeah, just you know, for for
lay people, for people just getting into finding. But yes,
so so this thing.
Speaker 2: So that's easy to see in bamboo, but in all plants,
you really want to have these your bundles connected somehow,
so they're not just not just independent strings of Christmas lights.
Speaker 1: And so.
Speaker 2: Usually everywhere there's a leaf, at least some bundles are
going to come together, if not all bundles, at least
some bundles are going to come together and share water,
share flow, share sugars and stuff like that. And in
the choices, that's what you're seeing that at the top
of the top of each of those where well, this
is where they come together.
Speaker 1: That's that's where a leaf was spinet exactly.
Speaker 2: And so and so if you could really very carefully
dissect the skin off of a living choya and dissect
the down through the cortex and get to the wood.
You'd find that the wood forms a zigzag that matches
where the leaves are.
Speaker 1: So those are nodes right where it comes together. It's
it's basically a way for all those fi the interconnect
not fibers, the plumbing, the InterPlaNet.
Speaker 2: Yeah, and that's a and that's a really big deal
that we don't know about in a lot of plants
is the interconnection of the plumbing. So so and we
have is the vascuar bundles, so in a in a
cross section of a stemia of individual bundles. So the
important thing is do the bundles come together at some
point so that they could share water? And and where
they do come together, do the do the vessels then
come together so that it's you know, it wouldn't be
any wouldn't do you much good if the if the
vascuar bundles came together, but the vessels in the bundles
didn't come together. So if you want to share water,
you have to unload water from this vessel through pranko
my cell, the prank and cell prank cell get into
this vessel.
Speaker 1: Just through plasma doesn'mount it. Yeah, yeah, So we're going
to talk about that by the if you don't know
what plasma doesn'mounter as we're getting to that, that's of
massive importance.
Speaker 2: Okay, So a much better thing is to have the vessels,
if the bundles come together, then have the vessels come
to gether, and the vessels gonna have their pitting between
the in the in the common wall between them, so
that water could be pulled from one into the other
and vice versa. And but we don't know that for
most plants, we assume that. And it's been it's been
shown in some in some palms by Tomlinson and co
workers that they were able to track where how the
vessels move, what their pattern is, and a and a
shoot and can they share water? Do they not share water?
Stuff like that, and think of it in a petiole
and a lot of diecots, a lot of you die
kots have three vescue bundles that will go to the
base of the petiole and then then do they stay
as independent veins up the petiole and into the leaf
and some plants they do. So if you could really
carefully cut through the edge of a petiole. You'd cut
one of those three and then one third of the
lamina could be really you know sol. But in other ones,
those three bundles come together, share water, share everything, and
then they they break up into a whole set of
bundles that runs through the petiole. So if you cut one,
no problem.
Speaker 1: There's smaller bundles.
Speaker 2: Yeah, and then and then again at the top of
the petiole they might join again and make another nexus
and then spread out through the whole lamina. But again
we don't know that for most plants that it's all
great theory.
Speaker 1: But the lamina being the leaf blade.
Speaker 2: So and this is this is something that is really
cool that in some old experience experiments and then maybe
some newer ones that I don't know about, that what
people would do is, you know, with a really sharp
pointed scalpel, take a broad leaf and just cut on
two little little nicks in the lamina and say, okay,
is this is this going to cut off? So so
you've got a mid rib, and you've got the lateral
veins coming out of the mid rib, not going out
to the edge of the leaf bank of the leaf blade.
If we cut one of those, is all the tissue
outside beyond that gonna die of dehodition. And for the
most part the tissue survives that the network is able
to get water around that cut and keep it alive.
Speaker 1: But but.
Speaker 2: It it seemed like, well, it just seems like we
need a lot more studies of stuff like at how
much of a safety margin is there built into these
things now? On leaves, most plants have thousands of leaves.
So if one, if part of one gets screwed up
by having a broken bundle and it can't conduct around it,
who cares, Well, we lose that one part of the leaf.
We've got thousands of the leaves, all of which are
functioning just fine. Yeah, So how important it is we
don't know. But it just again, it'd be a simple,
simple studies that might have that might surprise us. That
might surprise us, and that would That's been something I've
wondered about in cactus cortical bundles. If you could take
a cactus with the really thick cortex and a narrow
ring of bundles in the center, if you could just
saw through the main bundles the main wood, could the
cactus conduct enough water upwards through just the cortical bundles.
Speaker 1: That which are much smaller than the main which.
Speaker 2: Are much smaller. Yeah, but nobody's ever nobody's ever counted
to say, well, yeah, there are ten big bundles in
the center, and each of those ten big bundles has
five vessels that could conduct so much water. But out
of the out of the cortex, we've got two hundred
cortical bundles, each of which has one or two vessels
that altogether, the conducting capacity of the cortex is much
greater than the center.
Speaker 1: So that yeah, so that cortex, I mean, that's the
that's the key takeaway here though, on especially when you
think about something like grafting. That cortex is conducting sugars
and water with those cortical bundles. And that's why, like
I think about when I grafted that, I laid a
kind of series postel gray the pencil cactus, cut it
in half, cut the stem in half, laid it down
horizontally on top perpendicular to the tissue below on the stock,
and it still takes. It takes, and then it just
sends out. It's crazy. It's the weirdest thing.
Speaker 2: Yeah, I would guess what did you graft it onto?
Speaker 1: I would guess way bigger. So it's like a quarter
sized graft, like cutting a pencil in half and then
graphing it onto like a.
Speaker 2: So it'd be interesting to do that again. And then
if the graph is successful after a year or two,
you know, cut it open. Look are the are the
cortical bundles become woody and big and conductive or is
it just really only a connection between the main centrals
you'd be able to see.
Speaker 1: I would guess those cortical bundles are the main cambium.
Speaker 2: I would guess.
Speaker 1: So, yeah, okay, I'm gonna see that. I'm gonna make
a bunch more and then we gotta go and there's
come busy you we got to look at them under
the scope.
Speaker 2: Well, I think I think a big deal is that
there's so much that can still be figured out by
just doing but just looking, you know, just.
Speaker 1: Well questioning, having a question at it.
Speaker 2: Yeah, exactly that that.
Speaker 1: I'd tell that.
Speaker 2: You know, my research over the years, so many many
years could be done with just a handful of dollars
and I just simple microscope.
Speaker 1: But slicing those things that's the only hard part probably
is like slicing it thin enough to look at.
Speaker 2: But a lot of times you can just do that
with hand section, just just a razor blade and raise
braided and steady hand and yeah.
Speaker 1: It's yeah, God, it's so cool. It's wild stuff to
think about. Okay, well, okay, So moving back on to
roots though, and I still want to talk about intercalorie marastems.
We're putting that out there because that's a monocot specific thing, right,
intercallorie marastimes. It's basically yeah, I mean just the you know,
like the way that a lawn, the way you can
mow along forbid forbid, you know, but it's you can
mow it, but it's growing from the base versus you know,
like something like a shrub or something is growing from
apical marasims at the top. Yeah, what's well, okay, well
let's talk about this now. I guess okay, we'll save
the roots there. I want to talk about what's going
on with that. Okay, explain that where there's marastimes and
a lot of monocops do that.
Speaker 2: Yeah, So, what so joays talking about with interculary mirrors
stims is Mirraorsims are often classified by their positions. So
if they're at the tip, there's a an apical marsine
with the base or a bas of maristam. If they're
in between the top and the bottom, they're an interculary
mirror stem and and intercular mirrors stems of grasses of
lawnsi you mow that is in a leaf where the
it's kind of at the base of a leaf. It's
the base of the blade between the blade and the
and the sheathing leath. So in monocots, in most monocots,
the leaf blade doesn't just come down and attached dirt
into the stem. They do in a ga base put
in grasses and in palms, the leaf blade comes down
and then you get a thing that wraps around the
stem and goes down for quite a ways, and that's
the sheathing leaf base, and so the the and that
gives a nice stable, stable attachment point to the to
the lamina to the leaf blade, and that sheathing leaf
base often goes all the way around this stem. And
so I just talked about you die coos off and
have just three rescue bundles going into them. And these
monocods typically have dozens or in the big palm leaf
will have hundreds and hundreds of ascube bundles going into
this sheathing leaf base and they run up that base
and then into into the leaf blade. So you have
a really good connection in grasses uh an irises, and
a bunch of things you have at the base of
the blade is a mare. So so the blade you
can cut off the tip of the tip of the
leaf blade. And but you haven't heard the basal mara
sam with the intercilary marrasim because that keeps growing. And
so this the leaf lamina leaf blade will keep getting
longer and longer and longer, and so you can keep
mowing your lawn over and over and again. Now you're
not mowing the same leaf year after year. Each leaf
will finally stop growing. But the lawn is rhizomes have
spread and setting up new leaves that you've got to
cut off.
Speaker 1: Right. But this is why bunch of grasses can't be
made into the lawns because they don't spread by rhizome,
spread by raisomes.
Speaker 2: Yeah, but like let's say you're doing with this with
this with an iris, you could you next you know,
next spring, when your irises start to grow. Just cut
off the tip and you can watch and measure how
long and how much lamina is left down to the soil.
And then you can just watch it measure how much
it grows, and you can do that over and over again.
But at some point it's going to stop. That the
inticular amrastime just stops. So so grass leaf, if you
don't move your long your grass leaf is not going
to get infinitely long. And an irish leap or an
agabi leaf will not get infinitely.
Speaker 1: It will reach a certain length and then stop and
then to flower it'll send up another and entirely separate.
Speaker 2: Yeah.
Speaker 1: The bud that sends up that inflorescence is down at
the end.
Speaker 2: Yeah, And it's going to make them. It's going to
make more and more new leaves instead of have the
same old leaf just get longer and longer and longer.
Speaker 1: But interclory marastims, does that apply strictly to monocots? You
get in dicots at all?
Speaker 2: Or no? Let me think.
Speaker 1: I would imagine it's mostly monocots.
Speaker 2: I think mostly monocots now with spines. We call that
a basil marrastem because there's really the tissue below the
spine marrestem is not more spine. It is it's you
know this this stem shoot, it's the shoot body. So
then there's the marristam at the base of each spine.
Speaker 1: Yeah.
Speaker 2: So because it's the base of the spine, we call
it a basal marrot stem. If we were say halfway
up the spine, then we so we'd have then we call.
Speaker 1: It ins that branches. But I've never thought about that
and cact that for some reason, Like in an aerial
is there an applical marrastem there where, Yes, there has
to be, because that's where the flowers are coming out
of one.
Speaker 2: Right, and and that apical marastim is making the primordia
for each of those spines. So the spines are modified
bud scales, so that actually bud marrastem, that accellent marestem
is a little short bud, a little short shoot that
is making leaf primority that turn into spines. And then
each spine rather than growing like a regular leaf, grows
as a spine with a basal marrow stem.
Speaker 1: But those marrow stems they can can they keep producing
flowers out of an aerial or yes?
Speaker 2: Yeah, So it's a it's just like a regular bud
on on on like cotton or anything like that, and
it could grow out to be a say and I
can prictly grow out to be another little pad, another
shoot more as a flower. And in most plants, most cacti,
most plants, if it flowers, then it's kind of one
and done. It's you get one flower.
Speaker 1: And because with cacti you only get one flower per areal,
correct normally, but in some once it's already flowered, can
that same aerial produce another flower the next year In.
Speaker 2: A small number of feces of cacti, and uh, in
a martillo cactus, they you have three or four or
five flowers at the same time from this one areole,
and then the next year they'll do it again and
do it again.
Speaker 1: Wow, and.
Speaker 2: Gradually you build up to have an obvious little spur shoot.
But this but you have to have a really old
martillo cactus. And and in prue you've got near ammonia,
and near ammonia does that like crazy?
Speaker 1: So but like peoti areocarpus, they never flower out of areoles.
They only flower out of the center of the plant,
of the direct that they're.
Speaker 2: Flowering out of. They're flowering out of super young areals,
it's still the center of the plant, right right, right,
So every cactus flower is coming out of an aerial
but older areoles.
Speaker 1: Once that tissue divides and moves away from the center
of the plant, like in of paoti, they're not they
don't flower anymore.
Speaker 2: And again that's that's pretty much species by species, so
really easy to see. In mammalarias, they're very often mammalarias.
The areas have to be say one or two years,
three years old, get that beautiful ring that's a certain
distance from the apex. That and that distance is one
year's growth or two years growth. So whereas something like
like peyote or areacarpas they grow, they flower from super
young areas that are still down at the very y.
Speaker 1: You know, I mean physiologically like if you look at
the I don't know. But then they can't do it again.
Speaker 2: Mostly they can't do it again.
Speaker 1: Yeah, they have to grow and create a new stem.
Speaker 2: That and that is a yeah, And that's a good point.
So in almost all plants they're going to produce with
some exceptions, they're going to produce one flower per axi
ray bud, and some of produced two or three a
little cluster like red buds with prusio cluster of flowers
from an axioy bud. And that's because that bud is
a little tiny short shoot and it's producing little it
has its own little axoy buds on it that heat
produce a flour. And yeah, in the most cacti, once
it's flowered, they can't flower again for some reason. But
then I can Martillo cactus near ammondia, Yeah, they do
flower and they all.
Speaker 1: The ways around it. And then you've got the cephalium
of course, like a melo cactus and disco cactus, which
are something that was a disocca God, damn it.
Speaker 2: Disco cactus.
Speaker 1: Always I always can yeah, okay, and and so like
with not to be confused with dio cactus, which is
another genus.
Speaker 2: Right, total different genus. But like in the cacta that
have a lateral cephalium where the cephalium runs down the side,
like an espostoos, so you have this zone that you'd
expect if we're anything like mammalaria, you'd have just flowers
coming out of the top of the lateral cephallium.
Speaker 1: But in s.
Speaker 2: Postoa you'll find a flower at the top this and this,
this latter of sophallium can be like two or three
or four feet long, a big long stretch.
Speaker 1: Of yeah, just like it's hilarious. Looks like a beaver
pelt on the side of a canic.
Speaker 2: Yeah, And that's the only part that can flower. All
the rest of the stem, same age can't flower. And
so you'll see it an s postoa that has a
flower at the top and a flower at the bottom,
of flower of the middle, fruit at the top, a
flower at the bottom. So so you got some young areos,
you've got some old areoles flowering at different ages.
Speaker 1: What are they doing? Then they've just got so many
buds stacked up in that who knows?
Speaker 2: Who knows?
Speaker 1: That's crazy. Nobody's researched, and it's yeah, wow, okay, so
all right, well, moving back to roots. This is and
this is why I think what blows people's minds, if
they don't already know it is that most of the
absorption of water and nutrient instead of root is occurring
in like the tips where the root hairs are, right,
But the root hairs are ephemeral too. They die after
a certain amount of time, and then that root is
no longer where they've died, that root is no longer
absorbing anything. It's just it's just the conduit. It's just
the plumbing. And so so most of the most of
the root, like if you dig up a bush or something.
Is why it doesn't work when people are like, I
want to move a plant. Most of the root when
you dig it up, you're cutting off all the Yeah,
you're cutting off the part unless you're getting a giant
root ball, you're cutting off the part that's doing all
the absorbing and nutrient uptake. And you might have this
big root ball, but if it doesn't have root hairs
on it, if it's all like the older root.
Speaker 2: There's no absorption whatsoever.
Speaker 1: There's no absorption, and so that thing's just gonna die
of thirst.
Speaker 2: So that's why you always transplant. If you're digging up
a bush or a tree, you always do that in
winter when there's when the planet is leafless and this
has no transpiration, is not pulling on waters, not losing
water from leaves. Yeah, and you sit there and again,
like I mentioned, it's so easy to see what the
shoes are doing, but we don't know really what roots
are doing. So you you transplant your tree in winter,
and it looks like the planet is just sitting there.
But soil is usually going to be warmer than air
in winter, and so the roots might not be mostly
are not going to be dormant, and so they're going
to be healing those cuts you've made when you dug
the thing up and generating new adventitious root tips or
or lateral roots are going to beat.
Speaker 1: Unless you're in a really high latitude spot like Chicago
in February or something.
Speaker 2: Yeah, yeah, well even then, you know, even then you
probably the the top few inches are going to be frozen, but.
Speaker 1: Especially with climate change and that doesn't even get that
cold and Chicago on the winters anymore.
Speaker 2: But you know, in most places the roots are going
to be active, and when maybe slowly active, but it
be active. So by the time spring has come after
you've transplanted your plant, then then you've got some.
Speaker 1: They've actually rowing. The roots are probably growing using stored energy.
Speaker 2: So you're getting a bunch of regenerated root tips and
root hairs and stuff like that.
Speaker 1: And if you have to transplant and the death of
summer you gotta remove, it's not going to work well.
It won't work in most cases. But you've got to
get a lot of the root all and then also
cut the shoots, reduce the shoots in that case. And
then but then you're just relying on dormant buds in
the bottom parts of the stem.
Speaker 2: So you're going to have a really bizarre looking plant
when you're.
Speaker 1: It's still gonna there's a chance that may not wak,
so you're still gonna be losing moisture through those cut
ends of the shoots.
Speaker 2: Yeah. Yeah, long story short is, don't ever transplant a
root or a bush in the summer. It's just going
to work.
Speaker 1: Yeah, it doesn't. Yeah, especially when it's hot as the.
Speaker 2: Thing, and it's it's so easy to think of, well,
you know, you're transplanting this thing in the winter. No leaves,
they can't full of synthesize. But but plants mostly are
full of starch you've got and they can. They can.
They can regenerate buds, they can regenerate new leaves grow,
they've got some storage starch and it's and so like
in my garden, I'm always trying to kill hackberry seedlings
because they elm seeds. They German German, and I crazy
as well cut them off at root level.
Speaker 1: They're wonderful natives, but they could be aggressive, right, Yeah.
Speaker 2: And yeah, and so there's a little bit of a root,
it's gone enough storage storage to get a butt active
and stand a butt up for this oil and start
making new leaves and yeah.
Speaker 1: So that's hilarious. Yeah, man, it's crazy the types of
things that we don't think about. Yeah, that I'm gonna
move plants thing always drives me nuts. It's like, oh,
you just move it. It's like, man, you can't. It
doesn't work.
Speaker 2: Like like coming here, I saw a truck driving down
the road, you know, real borrow and all the all
the gardening stuff and a bunch of plants in the
back of a pickup leaves driving down the road at
seventy miles an hour, and the leaves are just you know,
it's Texas that's hotter than heck, and.
Speaker 1: Well, especially with it when it's dry, it's just soaking
those plants.
Speaker 2: Those plants are almost certainly dead by now. Yeah, So
it's it's just crazy to.
Speaker 1: See maybe cover them with something if you can, like
mitigate because the humidity loss especially. That's anothering people don't
think about, is how much humidity affects plants, Like the
humidity is really important. If you're trying to grow plants
inside in Chicago in a winter when the air is
exceptionally dry because it's so cold outside, you bring that
air inside heat it up. War amer can hold a
lot more moisture. You know, it's the capacity the relative humidity. Yeah,
and so that's you know, plant it's so easy to
kill shit growing in indoors and really cold climates. But also,
I mean, I see that being on one hundredth meridian
here in Texas, and I talk about this all the time.
I probably don't emphasize that as much as I should.
But West Texas and South Texas are completely different. You
get the same so many of the same plant species
growing in both places, but with different ecotypes in South
Texas where it's more humid, in West Texas, where it's
more arid. And it's not just the aridity, but it's
how the aridity affects the nighttime temperature too. You get
huge temperature swings. In West Texas, it'll be ninety during
the day, it'll cool down to fifty eight at night.
Never happens. In South Texas it'll be one hundred degrees
ninety five degrees during the day cool now to maybe
seventy nine at night. So I mean, how does that
affect plant metabolism? How does that affect I mean there's
so that humidity holds so much warmth. Yeah, and it's
shipped down there, grows so fast compared to here. I mean,
I killed my lawn. I have like a forest within
two years, you know, and the stuff up here, you
kill the lawn, it takes two years. You've got shit
that's waist high if that. You know, it's just the
much more arid climate. And you see it in the
plants too. The ego types in West Texas have thinner leaves,
et cetera.
Speaker 2: And just watering is not necessarily enough to make up
for that atmospheric community.
Speaker 1: No, no, it's not for the lack of atmospheric community.
Speaker 2: Yeah, the lack of atmospheric commidity here. One of my
favorite cacti is Perscia, the cacti that look like ordinate
trees with big leaves and stems, and you can grow
those except for the winter cold in Austin you can.
Otherwise they do fine, they grow and everything. You can't
grow them at all in Phoenix that you can water
them and water them and water them, and they just
don't make enough.
Speaker 1: There's shoots, it's just being pulled out so quick.
Speaker 2: It's pulling. It's big. That dryer pulls the water out
of the leaves faster than the shoots can conduct water.
Even if they have water in the roots, then the
shoots can conduct water to them. But if you've got
in an area with higher humidity, then you just find
that that the leaves are not losing water as much.
Speaker 1: And even just I mean just just environmental plasticity or
you know in a plant, you'll see you know, if
you grow it in a dry climate, the same individual,
if you grow at any more human climate, might produce
big leaves. But you grow in a drier climate and
the leaves don't get that big, and the leaves just
only get And that's not an ecotype thing, that's just
you know, plasticity.
Speaker 2: Yeah, response to stress.
Speaker 1: Yeah, this response to this environment. It's just dependent on environment.
I've seen that same thing. I remember I was really
obsessed with the medicine coil, which is love is a
humid plant. It's a humid plant, you know, grows all
the flood zones. Yeah, the Don Redwood, and I was
trying to grow them in Oakland like fifteen years. I
just got obsessed, which is Oakland's not that hot, it's
like coastal California, but it's super dry. In the summer.
You get six months of just really arid and they
just I water them every day and they still just
weren't growing that fast and looked like shit. I did
it with American chestnuts out there too, and once you
put it in the ground, then it's different story. They
can do a little bit better, but especially growing it
in the pot, you're just watering it every day, and
it's just the pot loses moisture so quick and they're
just transpiring too much.
Speaker 2: One of my favorite plants is monkey Puzzle around Carria. Yeah,
I'll carry bid Willie and uh I would. I would
just love to be able to grow that. But they're
like the downward where they have got to have fog
and mist and humid air and cool air, and.
Speaker 1: They've got at least thicker leaves though, and they've got
more like sclerophyll type leaves very much, very much much
more cuticle probably in wax, yeah, a little bit more
resistant to drying up. Those are great trees, but they're
so cool they get I think.
Speaker 2: I think if they if they were in a nursery
and saw that they were going to be shipped to Austin,
they would die right there. You wouldn't have to get
to Austin before they'd kick the bucket. Yeah, No, they
just don't make it.
Speaker 1: So what's going on with that then? Like why? I mean,
you can be supplying endless water to a plant, but
if it evolved in a place with humidity, it's and
then you put it in and the air is dry
where you're trying to grow it, is it just pulling?
Speaker 2: I think the amount of conductive capacity in the wood
in the asylum that it just is exceeded by how fast.
Well that's exactly what we're talking about bundles, that you
have a certain amount of capacity and if you're if
the top is evaporating water faster than you can conduct
it water up to it. Even if you have plenty
of water and the roots, you just can't do it.
So Yeah, I remember a class I had one time.
So so I used to teach in Austin and I
had a plant anatomy class with some kids from some
students from Houston, some students from Arizona and I asked
the question of describe what kind of adaptations you'd find
for a plant that's adapted to Austin and and the
Houston kids said, well, in a desert like Austin, you
have to have all these xeric adaptations, and the and
the Arizona students said, well, in a tropical rainforest like Austin,
so it's own's perception.
Speaker 1: Yeah, it's all relatives what they're used to.
Speaker 2: Yeah, So the Awesome people thought that we're just too
humid to survive, and the Houston people that were too
dry to survive.
Speaker 1: So it's cool. It's for me, it's just fascinating to
think about. I mean, that's one of the best things
for me about being in Texas is you're right where
the continent starts to dry out and you see it
in all the plants. Yeah, and we're starting with the
Edwards Plateau. It's where you start really getting some of
the hairer plants and the North American continent. And then
the extreme of that is like in the Mojave Desert,
where it's everything's all the plants are fucking white, you know,
like they're so dense with hairs. Are tomicon, the bear
poppy Salvia Fune area funeral stage just just covered in hairs. Man,
you could see how much that dry air affects, right, And.
Speaker 2: We were talking earady about the idea of humidity and
moisture and desert adaptations and so like. In you know,
even in the worst desert, you're going to have some
streams that always have at least a little bit of water.
So so you're gonna have a plant here on the
hillside that is it's dry air and dry roots all
the time, except after a rain and a few feet
away you've got a plant that has dry air and
its roots are in this wet stream soil, and they're
gonna have totally different biologies and totally different leaves and
like cuticles and stuff like that.
Speaker 1: God, what is that? I can't believed forgot the name
of it. It was one of my favorite plants. Is it?
Yerba manza? The plant that I can't remember the genus
name of it? Now, Jesus Christ, I haven't seen because
I guess you get it in West Texas, but I
haven't seen it in so long. What is the anyway?
But it grows in play it grows like in the
Mohave desert, but it occurs in seeps. You know, you
get Epipactis gigantea growing in Death Valley, but in seeps. Yeah,
the same orchid you get in ri paring areas here
grows in Death Valley as well. Yeah, there we go. Okay,
come on, Animopsis californica. I can't believe I forgot that
it escaped me. That's weird. Okay. Well, on that note,
I want to I want to ask do you think
you know, for people that grow cacti from seed and
they've got them in these humidity chambers and they keep
them in there for six months to a year sometimes less,
how does it affect the growth? Because cacti being cam plants,
I would assume if it's humid all the time, they're
keeping their stomata open, right, But at the same time,
the way that they photosynthesize, they've got to close their
you know, most of them take in stomata or open
their so nomata at night, taking CO two at night.
They close them during the day.
Speaker 2: And then you also have and so that would be
obligately calm where they have to do this no matter what.
And then you have some plants that are facultatively CAM,
where if it's cool enough and if it's wist enough,
then they won't do CAM metabolism. They can, but they won't.
They'll just leithers. Some are to open during the day
and do regular C three photosynthesis. And I don't think
there's any way to just look at a plant and
guess which it is. And I don't know. It could
be that a bunch of people have studied this, and
maybe that most cacti are obligately CAM, but I think
that I think that a bunch of them, and maybe
even especially seedlings, might be facultatively or that they only
survive if it's springtime, is cool enough and wet enough
that they can grow as C three plants until they
get to be a certain size, and then at that
point they'll switch to being CAM. I think I don't
know that for sure.
Speaker 1: You think some cacti can just be regular old C
three plants. I know they grow a lot faster as
seedlings if you keep them in humidity, like when I'm
growing a bunch of the native cactive for the Rio
Grand Valley. They grow, I can get them so big.
Speaker 2: Yeah, I don't know. I don't know, So it could
be that this has all been investigated and is written
up somewhere.
Speaker 1: When you keep that human, I mean certainly, if you've
got the humidity up, it's much easier for their stamata
to be open. Yes, because they're not the atmosphere is
not pulling as much water out of their stamata. But
and if they can keep their somata open, they can
be taking in CO two but more often than they
otherwise would be.
Speaker 2: Yeah, and that's a that's a physiology. So I'm a
plant anatomist. You know, you can cut plants open and
look at what's going on. And I have tremendous respect
for a physiologists because physiologists you've got to do experiments.
Do they grow better? You give them this water, grow
them like this for months and months? Do they grow better?
Do this? Do that? Do that? So you have to
do all these experiments and then interpret what's going on.
You can't just look and see like an anatomy. So
physiology is a lot harder. But with stillmata, you can
just look at those and say are they open or
are they closed? Or you can put a little instrument
on there and you can detect is water vapor coming
out of the plant or not coming out of the plant,
So don't know if the stilla open or close. So
the control of still model opening has been studied a lot,
and as you would guess, there are a million aspects
to the control of that. So most plants dawn, dawn,
light comes down, you open your stomata for your C
three plant camplant dusk, the sun goes down, you open
your stomata. But if it's water stressed then and the
plants really is suffering, then that light doesn't matter. The
still model will stay closed.
Speaker 1: But generally it's the light you would assume that it
controls the model opening and cactive.
Speaker 2: For instance, everything's okay, but if everything is not okay,
if you're water stressed, then that light is overridden by
other steps. And if and if that is wrong, then
that's overridden by other things, and then that's overridden. And
that's what it is. It is an exquisite area of physiology.
Speaker 1: There's so many different factors that's take into account.
Speaker 2: I wonder, yeah, and so the so the first you know,
the first the first reasonable assumption is yeah, light C
three cam stuff like C four, But that can only
be a first assumption. But you can't you can't be
sure because like you get the drought varieties of cotton
that most cotton is just takes a huge amount of
water because because it'll just transpire like crazy, and and
if and we'll just die if you're not watering and
like crazy. But you have drought ress cotton that can
close this stone in the daytime.
Speaker 1: And so they'll was that that was bread or what?
Speaker 2: Yeah, And so they can they can survive. They might
not thrive, but they can survive with less water because
they're not following the regular rules. Are they cam?
Speaker 1: Are they are they doing camera?
Speaker 2: Don't? I don't know. I don't think so. I would
doubt it.
Speaker 1: Yeah, that's the And that's that's the other thing too
to think about with growing some of these things, like
for growing cacti for restoration, like if you germinate them
in a humidity dom, how do you acclimate them to
lower humidity? Probably it's much easier in the Rio Gram
Valley where it's more humid than out here in West
Texas where it's exceptionally dry. But in how long, like
what are you doing when you're acclimating it? That's what
I want, are you waiting for still model density to
be reduced in the new growth or what?
Speaker 2: Yeah, I don't know, And that is that is you know,
and that could probably that might be all out there
in the in the horticultural literature, because no matter what
you're doing, that acclamation from you know, in in a
mis chamber and a growth chamber.
Speaker 1: With people doing cuttings, right, or if.
Speaker 2: You're growing if you're growing orchids from tissue culture and
you're generating a zillion little orchid plantlets from inside of
a test tube with one hundred percent humidity, you can't
just plant them out so so that that.
Speaker 1: They'll just wilt, Yeah.
Speaker 2: Getting them acclimated. What actually happens? I would guess that
during acclamation there's something synthesizing a whole bunch of cuticle
on epiderma and and wax. But but I don't know,
I don't know.
Speaker 1: I don't even think about that.
Speaker 2: And it could be different from.
Speaker 1: From plant to cuticle, and free is produced in the epidermis,
not just at the apical maris, then that's.
Speaker 2: No from the epidermis. And and how long how long
an epidermis can synthesize cuticle or wax that probably varies
from plant to plant to plant.
Speaker 1: Yeah, and can it regenerate it if it's been and where.
Speaker 2: That can regenerate, I don't. I don't know if any
plant can regenerate cuticle if you would say, strip it
off or you can't really dissolve it off the way
you dissolve wax as you like with ether or chloroform
or something like that, which of course is going to
kill your plant. But let's say you would you just
take a razor blate and scrape off.
Speaker 1: Like plandilia, like any.
Speaker 2: And so next time I see you, I'll expect that
you've done that.
Speaker 1: That'll be But on that plant, that's not just cutical,
that's farina too, that's the And for you said varina
is long chain fatty acids. Cuticle is I.
Speaker 2: Think varina is wax, wax pellets, wax particles.
Speaker 1: Yeah, yeah it is, yeah, okay, but how does it
differ structurally from cuticle?
Speaker 2: Cuticle is usually made up of cutin, which is shorter
chain fatty acids. But apparently, and lots of plants, what
we think of is the cuticle that we used to
think of just being a pure cutan layer has pockets
and lens and lenses and patches of wax in it,
so the cuticle is both cutin and wax. And then
a lot of plants then after they've made their cuticle,
go on synthesizing the the long chain fatty acids.
Speaker 1: They need for wax, producing more weight.
Speaker 2: And then that those long chain fatty acids just move
right through the cuticle and cumulate onto the surface and
then polymerize into wax. And and in some plants, and
some plants they plummerize in a nice smooth surface, and
other ones with different fatty acids. They'll they'll make plates,
they'll make spirals, they'll make blobs, they'll make all kinds
of different needles, shapes, and and a lot of times
the it's only the cells right around the guard cells.
So either the guard cells themselves or the next cells
out called subsidior cells, they will synthesize special waxes that
then will grow out the waxes plumerize into these needles
that that over arched system model pour so carbon dioxide
can still get through easily because it's just needles. But
if you have rain or mist or dew, then those
water droppers we're gonna that drop is gonna form a
We're gonna sit on those needles and it's not going
to get down to the model poor and block the poor.
So carbon dioxide, even all that water molic water droplet
is sitting there on top of those needles over the
sumadel poor, the carbon dioxide can get around it and
get into the plant. Whereas if they didn't have these
special waxes right around the this the poor, then the
then then do or whatever it might just phone then
film block it and you're in the Yeah, the planet
would basically not suffocate, but would be cut off from
its carbon dioxide.
Speaker 1: Okay, so moving on from this and I'll let you go. Okay,
I didn't even realize it's been an hour and forty
five minutes it's been. It doesn't feel like that.
Speaker 2: Before we move on, So we're talking about epidermis. Let's
go back to those those missiletoes that get inside the
host of their plant. So you know, epidermis is such
a crucial feature to survival and and the cuticle and
the waxes and stuff like that. Now, if you if
you can strip off the the epidermis of a cactus
would die out in West text it would die within minutes.
But here we have these mistletoes that are inside their
host plant. Don't make any epidermis, don't make any cuticle,
don't make any wax. Of course, they don't need it.
They don't need to conserve water. They're in a watery plant. Yeah,
so it's it's again the idea of something that seems
to be such a fundamental feature of plants, an epidermis.
We don't need it.
Speaker 1: We just a lot of aquatic plants don't produce cuticle
or even stomata, which is wild, right, right, they've just
lost it. They had it at one point, but when
they went back into the water.
Speaker 2: They yeah, and in most The one thing I find
extremely bizarre is the epidermal cell. Epidermal cells are the
most exposed to sunlight and carbon dioxide. They don't have chloroplasts.
You know, there are some reports of microscopic, super microscopic
chloroplasts and a few epidermal cells. But if you just
take a pure epidermis, it is not going to be green.
You look out of the microscope, you see chloroplasts all
over the place, and so all the photosynthesis is done
deeper inside the tissue and the prankima. Yeah, and the
cortex with a leaf mesa phil It's like, why on earth,
what's what's the advantage of that that that you're epidermis
is not for synthetic. But when you get into the water,
plants that live submerged, their epidermis very often has.
Speaker 1: Chloroplasts and show.
Speaker 2: Yeah, so something that we expect to be a fundamental
aspect of epidermis not in water.
Speaker 1: Filmy ferns are weird too. Filmy ferns are really hemenophylesi.
Speaker 2: Yeah. Yeah, well when filmly ferms are so strange because
very often between the where you have a vein and
a only fern leaf, you have an upper epidermis and
lower epidermis and some mesophyl cells on your zion flown.
But between the veins there's often just one layer of cells.
And I don't know if that's anybody's figure out whether
that's a layer of epidermis or music field.
Speaker 1: But yeah, that one layer of cells, does it have chloroplasm?
Is it doing any photo setting?
Speaker 2: I don't know.
Speaker 1: They're always in really humid places.
Speaker 2: I mean they have they have super humidity. They die
instantly in dry air.
Speaker 1: Okay, so Okay, let's let's talk about because this is
a wild thing. So plasmo desmata, which are essential, right essential,
but they're also what connect every cell and a plant
that's alive to every other cell. So you've got the
cell wall, you know, and like parentma colma, only a
primary cell wall sclaringkima secondary cell wall composed leg. But
you get the cell wall, and then you've got the
cell membrane beneath that. And like animals of course don't
have a cell wall. There's no cell wall. It's just
just the cells just have a membrane. What the membrane
Like when you were when we were talking about like
siguar was melting and Phoenix because it's too hot. The
cell membrane is a lipid molecule in LA, the layer
of lipid moleus. And you were making a comparison to well,
how does it like butter behave at cold temperatures versus
hot temperatures? And so what happens at hunt one hundred
and thirty degrees? You've got a fucking saguaro, you know,
planted in a mall parking lot. Yeah, and Phoenix, it's
it's probably not the cell wall which is composed of
cellulose that the primary cell well that is being affected
by those temperatures. It's the membrane.
Speaker 2: Yeah, yeah, So a crucial thing that we were talking
about earlier that that the membranes that the cell membrane
that surrounds a cell, or the internal membrane like the
membrane around the nucleus, or the membrane of the mitochondria chloroplasts.
Those are those membranes are a or two layers of
lipids that on one end one end of each lipid
molecule is is kind of usually a phosphate group that
is that makes it attract water, and the rest of
the molecules is a lipid, so it repels water. And
so if you mix those together in water and then
shake it up, then all the the the hydrophobic parts
are going to can avoid water if they associate with
other hydrophobic parts of other lipid molecules, and so and
the and the the phosphate ants can associate with water.
So you get these automatically form these these two layered membranes,
and inside these membranes you have a lot of proteins, enzymes, pumps, channels,
and those proteins have got to be able to move
around through that memorane, not not in and out of
the membrane, but just from side to side in that
layer of the.
Speaker 1: Membrane, in the membrane itself, within this trapped.
Speaker 2: In the membrane itself. So the memorane has got to
be fluid at least it can't be hard more than
if it's hard, then they then the proteins can't move
to where they've got to be. And so so think
of taking certain types of lipids and you like butter
sticking your refrigerator and it gets hard, and you can't
use that in a membrane of a cold area plant.
If you did that, then all the memories would get
hard and the plant would die. On the hand other hand,
you got things like olive oil, corn oil that that
even if you get them cool, there's still lick liquid
and will still fluid. But then when you get them
too hot, like phoenix one hundred and thirty degrees, then
maybe maybe they get to be too fluid and they
can't really.
Speaker 1: Serve as a membrane anymore. They're not holding anything in
or do they dissolve into the cell or what. But
that's probably what's happening.
Speaker 2: There's probably probably the there's probably the fluidity of the memories,
that the memories just can't maintain their integrity. And that's
and that's also a big deal about when when a
seed dries out, that such a crucial thing as you've
got to have you know, water on one side, on
the two sides that the membranes keep their their orientation.
That when you dry a seed out, that keeping the
membranes from just you know, just going to heck is
a is a tricky deal. And then but they do it,
and resurrection plants like Seleganella does it. They can dry
these things out to where how on Earth are their
membrane survive and then and then as you rehydrate them
that the membranes are still where they should be in
doing doing what they should.
Speaker 1: So that's a big So what happens to because I
mean the obviously many like some opunthia can freeze, some
frankly pairs can freeze, some of the small ones, yeah,
or potossa or human fuse or whatever. But then some
will just melt, like in that Texas freeze, they just
went flasted. What's actually being affected there it's not the
cell wall, it's probably the membrane. Or yeah, when when.
Speaker 2: When plants are killed by freezing, a lot of times
that's the formation of ice crystals. That you get an
ice crystal that the water inside the cell freezes or
entire they intercell, your spaces freezes, and then those crystals
puncture the membranes and so you gotta so a membrane
in a cell is just like a SOB blobal membrane
that has no edge. That it's that you know, once
you pop it, you pop it. And so so maybe
when an ice crystal punct just grows through a membrane,
it just pops the membrane until the cell dies and
you may not know it until spring, but you know,
basically the cell has dyed during the middle of the winter.
But yeah, and a lot of the and they're prickly
payers that often just just lay down flat on the
ground in the middle of winter and then the spring
they just perk right back up.
Speaker 1: Well, some of those ones in northern latitudes, because there's
a punty that grows up in Canada, I think, well
they turned pink. So they fill with betaline pigments which
has a which has a freeze protective you know, that's
like a protective pigment basically. But then I think they also,
well they also get wrinkled too, so they're kind of
they're expelling water and then probably filling with more sugar
and salutes to lower the freezing point of the inside
of their cells.
Speaker 2: Maybe that would make sense, I would.
Speaker 1: I did a video on this four years ago. I
just forget it. I just forget. But I mean when
you see him, you know, you see him like.
Speaker 2: You spend your whole life, your whole life learning stuff
and then you forget it.
Speaker 1: I know, yeah, if you're not doing you're not staying
on top of it and going through it again every
six months. But uh, but I know that, Like I'll
point the human fusa, like that cool prickly pair that
grows in the sand prairies thirty miles south of Chicago.
You see him in winter, they're wrinkled and fucking stressed
and pink, and then you see them in spring or
summer and they're like green, and.
Speaker 2: It's the same and it's the same.
Speaker 1: Yeah.
Speaker 2: Yeah, I've just been so that by too.
Speaker 1: It's weird. Okay, So all right, we'll moving on to
plasmo dismodel.
Speaker 2: This is this is the essential he's been bugging me
about plastic.
Speaker 1: This is all days on the connections where every cell
and a plant is connected to every other cell, and
animals don't do that.
Speaker 2: It's yeah, it's and that is a yeah, that's crucial.
So we needed to kind of start from the beginning.
So an animal cell is very easy to define. You
have a blove of protoplasm that's surrounded by a cell
membrane everywhere, and you take one animal cell and push
it up against another animal cell and there are two membranes.
Cell membranes come together, So when we say cell membrane,
we're talking about the outermost membrane of it. Now you
have inner membranes like the membranes of the nucleus, membranes
of mitochondria, and.
Speaker 1: Get the membranes of the organelles.
Speaker 2: So they are membranes in a cell. But when we
say cell membrane, we're talking about the automost covering and
the technical term for the technical term for that is
plasma lemma. But that term is kind of old fashioned now.
So it's easy to define a cell in animals that
is a man of protoplasm surrounded by a cell membrane.
In plants, it's not so easy.
Speaker 1: So the.
Speaker 2: Example I like to give you take those, you know,
cardboard and melk cartons that are kind of shaped like
a plant cell, and the cardboard is cellulose like this
plant cell wall. And you glue some mel cartons together.
Speaker 1: The little ones like a school lunch or something.
Speaker 2: Yeah, and you glu glue is together side by side,
and the glue is your is your middle amella. So
you really got a nice, beautiful, accurate model of plant cells.
But now you take that, take those and you take
a needle of some kind.
Speaker 1: Of and the way the littamella is what the the
middle of mello.
Speaker 2: Is the glue that holds plant sells to each other.
Speaker 1: Well, tell everybody what it is in the yeah, I
mean it's it's in between the cell wall.
Speaker 2: Yeah. So so this is the amazing thing that that
between one plant cell and another plant cell is a
layer of calcium pectate. And and you're familiar with calcium
pectate if you've ever made jam. What you're doing is
you're boiling the fruit.
Speaker 1: Oh it's pectin.
Speaker 2: Yeah, So you're just dissolving the middle lamela. And then
and then when you when you make your jam, you
just let it. The middle that now you're pectin is
now diffused with all that water. But basically when you
look at your favorite redwood trees, all those cells are
being held together by jam pack then by pectin.
Speaker 1: Wow, and it works.
Speaker 2: It's it's strong. You'd never guess if I'm looking at
jam but so so.
Speaker 1: In this milk carton model, so each milk carton represents
a plant. So you get a bunch of glue together.
Speaker 2: The glue is the middle, the middle of that's the
peck and that's swung them together. But now you take
a needle and you poke a hole through the two
milk carton to glue together, and the other two milk
dart and tot of glue together. And and now you
just take and poor paint into one of the cartons,
and that paint is going to flow through those holes
into all all the milk cartons. And then you pour
that paint out, and that paint that remains is your
cell membrane. A layer inside the layer that stays inside
is your cell membrane. And so it's you know, all
on the inside of.
Speaker 1: The connecting the milk cartons or the plasma that is
not right.
Speaker 2: And so your plasma membrane of one cell, it goes
through the plasma's model these little holes into the next
milk carton, the next cell, and it's that layer around
all of those, but it goes through those plasmia's moda
into the next milk carton, and the next melk carton
and the next milk carton. They're all connected, and so
you have all connected connected, and techniqually you got just
one single plasma membrane, one single cell membrane. And so
by the animal definition of a cell, a plant has
just one single cell that every single bit of protoplasma
in a plant is connected to every other single bit
of protoplasm in in the plant. And and so it's so,
you know, this is one of those things that botany
graduate students like to get think about when they get
drunk on a Saturday night. The one cellars are multiple
cells and stuff, which is kind of a useless thing,
but it's interesting that so when you know, you guys
something like a furn that's making spores, it's going to
release the spores, and of course, now the spores of
course cannot be connected to the rest of the plant.
So they've got to break down the middle lamella, and
they have to break the plasmidasmata and the plasma membrane
of the mother cell, and the plasmid is mada of
the of the plasma membrane of the spores have to separate.
And they do that now in in flowering plants where
the the like the like the where the egg cell
is being made and the or the mega well technically
the megaspores being made in the far distant past, that
megasphore would have been released when it's not released anymore,
but the plant still breaks all the plasma's mauna as
if it were going to be released. And yeah, so
it's really odd and very often when in the guard cell,
so that.
Speaker 1: That cell, that egg cell in an angiosperm is no
longer concted, no longer it's not part of that continuous
cell membrane exactly exactly.
Speaker 2: And and in at least a bunch of plants, when
the when the cell that's going to become the two
guard cells starts to form, it breaks its plasmia's mata,
at least some of them, and becomes isolated from the
rest of the plant. Wow, And it may be that
that helps it have its own physiology distinct from the
physiology of the nearby cells.
Speaker 1: I don't know if they're opening and closing and it's
dependent on turger pressure, right, wouldn't it.
Speaker 2: Yeah, that makes sense.
Speaker 1: That makes sense because there's nothing, there's nothing, there's no
other barrier, right, there's no there is no barrier between
well in the plasmata, like between one cell and another.
Speaker 2: But so the plasma is mata. So we just talked
about you're just punching holes into the end of the walls,
but they're a lot more complicated than that. In in
a real plant, each plasma is moda this hole between
two adjacent cell walls. It's lined by the plasma membrane,
by the cell membrane, but it has a thin It
has a thin tube of proteins, just a protein tube
called the desmo tubule, and the cell membrane. A sell
organelle called the endoplasma particulum comes to one end and
hooks onto the plasmadesma and on the other end and
the other cell some more endoplasma particulum comes on and
hooks onto the the other end of the plast of
the of the plasmadesma. So they're they're really complicated, and
if you microinject certain types of ions into one cell,
they don't necessarily automatically flow into the next one. So
it's not just an open hole that the plasma is.
Mada can control what goes through them. I don't think
there's any evidence that they can pump things through them,
but but they're not just open holes now, No, and
something like a fiber and sclank myselves, but typically die
when they're mature. Then at that point you still have
these holes in the walls, but since the cell is dead,
you no longer have the the plasma membrane or the
desma tubule or the endoplasma particulum. But we still use
the name plasmadesma, so you have to be careful when
you see that.
Speaker 1: Term, right, So it's a little more complicated than just yeah, yeah.
Speaker 2: It turns out to be pretty complicable.
Speaker 1: What was the other thing that we were talking about
today and the drive down where we mentionedgend because selaginella
are weird they do all this stuff.
Speaker 2: It was vessels.
Speaker 1: Oh, yeah, they have vessels, so.
Speaker 2: We think of we usually think of well of engines
from the flowering plants is having vessels.
Speaker 1: So xylum tissue. We have tracheads and vessels. Trakheads are
generally smaller, they've got a different shaped. Vessels are bigger,
more efficient, the transporting water all just applies to asylum
for anyone listening.
Speaker 2: Yeah, yeah, and and the and the wonderful thing about
vessels is that they tend to be very wide, so
they have low friction. And think about you, you're trying
to drink a milkshake. You're going to drink it through
a wide straw, not a narrow straw. But the big
deal is that vessel. Each cell of a vessel has
a big hole in this and where water can go
from one vessel's element, yeah, perforation, So so water can
go from one vessel to another just by passing through
this hole. So there's very little friction, and so water
can move easily through vessels. And a lot of people
and vessels we usually think of as flowering plant. So yeah,
and and a lot of you'll hear people say, well,
the vessels allowed Angi sperms to adapt to all kinds
of different conditions. But we have vessels occurred evolved independently
in Solaginella, and they also evolved in equisite them and
in uh and three conifers called uh efed will which
you and need them. So so vessels have evolved at
least four times and in three times in Solgenella and
equisite and this need them, et cetera. It's really not
led to any big success that they have these vessels,
and theoretically they can conduct water very easily, but that
hasn't let them take over the world.
Speaker 1: Like angiosperms did, right, or requires more than just updated
plumbing to whereas conifers just have traking. It's no condifer conference,
no gymnal Sperms except for the federal relatives have vessel elements,
right right, that's wild. Silaginella is just so bizarre. I mean,
it's got so many traits that it shares with angiosperms,
but it's totally unrelated.
Speaker 2: Andospory, yeah, and so the elements and so the heterosprey
means that it makes big spories and little spores and
and a big deal about that is is in flowering
plants and seed plants and all seed plants, the one
of the sports called the megasport is retained inside the
the mother cell body, and then that mothers the mother
plant body, and then that mother plant can nourish that
spore and protect it and get it take taken care of.
And that's what's going to develop into the seed, into
the embryo of the seed.
Speaker 1: Like all the seed plants are the spores and so
and so.
Speaker 2: The so the cruise thing in evolving to have seeds
is first you have to have this big this spore
that's retained inside the parent plant's body and the parent
takes care of and Selaginella has that first step. It
has big spies and little sports.
Speaker 1: Instead of just being instead of just being cast out
like ferns do, and the.
Speaker 2: And the big spores that the when that sport germinates,
it doesn't just grow like crazy bunch of cells. It
stays basically inside that megaspore wall. And so it's so
the next step would be for the parent plant to
retain that megaspore and let that megaspore germinate there inside
inside the host plant and the mother plant and then
grow to be a four under a seed and at
that point then let it be released. So so the
legend of the of the nine or ten steps you
need to become a seed plant. So Selaganella has taken
lots of those steps, but it hasn't made the last
few steps. Whether it ever will, who knows.
Speaker 1: It's still pretty cool to think about it.
Speaker 2: And another thing about Slagenella that you probably didn't know
is that if you cut a if you cut a
cross section of it, you'd expect to be, you know,
this solid cortex parankama and then a vascuar bundle or
set of bascuar bundles, and not in Solagonella. In selaganella,
you cut across and you have the cortex perankoma, and
then you have a hollow chamber. And this hollow chamber
that's where your zion floam were running. And there's a
little bit of parankama right around the xiomon flow and
that's supported by some little bridges, but for the most part,
the zyomon floam run through this big empty chamber where
all the cells are broken down. What the hell? Why
do they do that?
Speaker 1: Yeah?
Speaker 2: And it's you know, I can remember reading about that. Anything. No,
that can't be right, and so cut one open and sure.
Speaker 1: Enough, I'm so curious about the ones out here in
West Texas, like or any of the drought tolerant ones,
the desiccation, not drought, the desiccation tolerant ones that can
completely dry. Okay, Crispy, I'm so curious about, you know,
the process of them like a spore germinating and and
how a new plant gets established. Like I'd love to
see someone do that and horticulturally and just study it
how it you know what I mean.
Speaker 2: My guess is that people have studied that because it
is such a bizarre phenomenon.
Speaker 1: I think that I think there's papers in it now.
Speaker 2: So Lagenda looking to do that, and it's so Lagenda
is really bizarre because it's a big plant basket tissue,
complicated tissues. But you know, most all desert mosses do
the same thing that that maybe in spring every you know,
every spring or so, they dry out completely during the day,
just like Solagenala, and then you get in the evening,
you get dew forming and they hydrate, so in the
morning they're they're nice and fresh and green and happy
and and then carrying out the photosynthesis and then in
the afternoon they dry up again, right right.
Speaker 1: But the difference in in Solaginella is the gametophyte stays
inside the spore. Yeah, like even in the male sport. Yeah,
it's yeah, fucking weird. And so then it's got to
produce Anthridia and arcogonia respectively. But but how does the
sperm get out? You know, That's what I'm curious. How
does the sperm get out of it emerges out of there.
Speaker 2: So we'll keep keep in mind that the sperm are
formed in anthridia, right, so right in the sport in
the in the microgamedifyt inside the spore the microamedifi. But
the anthridia are tiny, tiny things.
Speaker 1: So you've got to get a microspore landing next to
a megaspore and.
Speaker 2: Then growing to a microgamunify near a mega gamutify with
anthidia on the male plant and archigonia on the female plant.
So yeah, and then when you have a film of
water when it's raining, then the antherity breakdown release the
sperm cells. The sperm cells become active. They've got flagella
and they can swim.
Speaker 1: They're still mobile, yeah, swim, and.
Speaker 2: So they can if the rain and then splashes some
sperm cells next to an and to an archigonium, they'll
swim down into the archegonium and for unfertilized the egg.
Speaker 1: There, but it's got to swim inside the female.
Speaker 2: Yes, that's crazy, but but the spore at that point
is broken open to the the gamaedify, the megagamedify, the
female gamedifyt is now visible through the broken the broken,
cracked spore wall, and the archigonia, the organized that the
organize actually make the egg are visible on the surface
of the communifed through that crack in the spot wall.
So the the range of splashes the sperm cells and
they swim to there. And and an important thing that
most people don't realize is that that swimming sperm cells,
sperm cells that have flagella just like our own sperm
cells and that can swim vigorously occur through all the
plants up to.
Speaker 1: The psychads and psycads and ginka are the only ones
that of the gymno sperms, yeah can go I'm not sure,
but yeah's got motile sperm.
Speaker 2: But in psychads psycha each sperm cell of the psycad
has hundreds of flagella. They're giant and they occur in
these big rows.
Speaker 1: Yeah, they don't look like human sperm, not at all.
Speaker 2: Yeah, they're just they're they're a great big and have
very hairy with all the all the leagil on them.
But we have plant cells that swim all the way
up into the seed plants.
Speaker 1: Yeah, god, yeah, the Kinkos man. And then you think
about all the stuff that's extinct that this is only
known from fossils. I had a paleo bonus on the
podcast the last year and they were talking about taking
c T scans to to some of these rocks so
they could get good three D images of these structures.
And he was just telling me, Yeah, we see shit
that we just don't know. It's so bizarre compared to
what like, we can't we know it's a plant, but
we can't figure out what it's doing. What's the reproduct
you know, what the reproductive structure is doing. What the seed?
You know, why does it seed look like this or
so nuts?
Speaker 2: Yeah, yeah, we have flowering plants. And then you know
a couple of species of selaginal unlike a podium and
equisiteum and ferns, and these are the remnants of groups
that used.
Speaker 1: To be huge and comprise these major linea.
Speaker 2: Yeah, lots and lots of diversity, and we just don't
know what they look like, and especially so legend and
like William Thatt there that they're a whole different line
of evolution from all the seed plants and ferns, and
so they're their ancestors are big trees.
Speaker 1: Like isoetes, that's the modern day descendant of these things
that the lepidodendrons.
Speaker 2: Yeah, yeah, yeah, great, big leaves, huge reproductive structures.
Speaker 1: That form the coalbads of you know, most of the
coal bads these three hundred and twenty million year old covids.
And how different was the planet of look back then?
Speaker 2: That I would love to have, I would love to have.
You know, some palaeobotanists team up some really good artists
and try to come up with, oh my god, I
know we have a few reconstructions. Yeah, they look at.
Speaker 1: A mural in my bathroom. Yeah, a carboniferous coal swamp.
And then but then you think about all this shit
that just we haven't found yet, we'll never know exists
because it never got fossilized. Yeah, it's crazy, it's madden
to think about. It's really fun to think about.
Speaker 2: And you know, one time I was in the the
Eric Carrier forests and and uh, in Chile and Eric Carrier.
You know, there's worlds of worlds of branches. Yeah, being
real prehistoric and in that being in that forest where
everything nothing looked familiar, nothing looked right and compared to
what we know today, and and yeah, just imagine what
was It gave you a.
Speaker 1: Little taste of what it might have been like, you know, yeah,
three hundred million years ago.
Speaker 2: I think, what would it be like to be an
Archaeoptre's forest or these other fossil trees?
Speaker 1: And that's so fun to think about it. Man, Well, thanks,
it's two hours fifteen minutes. I could keep going, but yeah,
I don't know if anyone We've probably burnt out some
of the this is good stuff. I mean, I think
I think again, once you once you get a basic
understanding of the different tissue ties and what you know,
what's composing, you actually think about like a three dimensional
view of what you're what's going on in a plant
that you're looking at. It helps to start then asking
these questions. It gives you what you need to start
thinking about this.
Speaker 2: I think, I think a fun way to look at
look at it is so think if imagine you're a
carbon dioxide molecule, and you've just bounced into a stoma
in a leaf and you've been caught by chloroplastid turned
into a part of a sugar molecule. And how you're
being transported through the floam and where do you go?
What are you passing through? Or your or your a
nitrate molecule that gets absorbed by a root and you're
going up through the through the asylum and some enzyme
catches you and makes you into a new amino acid
and part of a protein protein. What cells do you
go through? And what walls do you go through? What
plasma is might And it's it's fun to just you know,
next time, you're next time you just don't want to
get out of bed, you're you know, Saturday of alarm's
gone off, you don't want to get out of But
just today, what would it look like if I was
a molecule?
Speaker 1: Yeah, a carbon dioxide molecule. You could end up in
a dandelion. You're put back into the carbon cycle really quickly.
You could end up in a fucking redwood tree and
you're entombed for twenty five hundred years.
Speaker 2: Yeah, and then you end up in a cold dead yeah,
And you're there for millions of years.
Speaker 1: Yeah, so that's fucking crazy. I didn't man about that.
Speaker 2: I spent hours think you've been on Saturday instead of
instead of getting up and doing my work.
Speaker 1: Well, Jim, thanks a lot, man, I appreciate it. Right,
everybody else, have a good rest of the day. Go
fucking somebody,