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  secondary hemiepiphytes
From: alan san juan kalim at erols.com> on 2000.05.18 at 19:19:54(4593)
I have two questions, maybe someone can help:

Monstera deliciosa is probably the most famous example of plants that
may start out as seedlings in the soil, before climbing up trees and
(maybe) slowly dispensing with its connections to the earth.

(1) I'm wondering whether anyone has any other examples of this in the
aroid family.

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From: Paul Tyerman tyerman at dynamite.com.au> on 2000.05.19 at 11:51:49(4594)
At 09:20 18/05/00 -0500, you wrote:
>I have two questions, maybe someone can help:
>
>Monstera deliciosa is probably the most famous example of plants that
>
>(2) Is there any evidence or explanation as to why any plant would elect
>to dispense with a ready supply of water by doing this? Is there some
>energy consideration involved (eg., too expensive to maintain
>connections to the ground)?
>

As I understand it the reason that the Monstera would cut its ties to the
ground is that it is trying to reach the canopy of the rainforest to get
the light it needs for growth/reproduction. It heads for the tops of the
trees to get more light. Sometimes it is able to get enough water through
its adventitious roots that emerge along the stem, so it dispenses with the
connection to the ground. I suppose that in this case the Monstera becomes
epyphytic as epyphytic plants use other plants for anchorage and draw
moisture/food from the surrounding environment through the support roots.
There are so many epyphytic orchids out there that absorb everything
through their roots way up in the canopy of the rainforest. Seems to me
that it achieves the same result, but starts in the ground.

I also seem to recall that when a Monstera seed germinates it has internal
reserves to grow up to 6 feet in length. If by that time it hasn't found a
tree trunk to climb then it dies. The climb into the canopy is a genetic
imperative (as well as just plain necessary to get enough light and moisture.

That's how I would see it anyway. Anyone else out there know for sure?

Cheers.

Paul Tyerman

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From: "Hans E.A. Boos" trekmaster2001 at yahoo.com> on 2000.05.19 at 11:52:59(4595)
Dear alan,

I have grown Monsteria to flowering and seeding, and
this may be only a partial answer to your question.
The plant, being so huge in its leaf structure needs
more light up in the canopy than on the dim jungle
floor, hence the need to abandon its earthy roots.
Hans E.A. Boos. Trinidad and Tobago

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From: SelbyHort at aol.com on 2000.05.19 at 11:55:08(4597)
In response to Alan's questions: Plants have adapted to epiphytism primarily
to get up in the canopy where there is more light, less competition from
other plants, increased pollinator activity and possibly for protection from
ground herbivores. The tropical forest floor is extremely dark except in
forest gaps. Plants that have developed either hemi or true epiphyte strategy
are often rewarded with greater or more efficient pollinator activity, more
light, better seed dispersal, additional nutrient from cloud and other
advantages. Many of these hemiepiphytes are from high rainfall areas that are
wet rather constantly year round, so they can get a lot of water either on
the ground or up, so electing to stay at ground level provides few if any
advantages.

True epiphytes have a different root structure that allows them to very
efficiently absorb and hold even trace amounts of moisture very quickly. They
can grab moisture and nutrients from the rainforest clouds as they pass
through the canopy. Other epiphyes in the canopy, such as the bryophytes,
release nutrient into the cloud water as the cloud passes through, and plants
nearby can absorb this nutrient readily as the nutrient saturated cloud
passes over them. The cloud also picks up nutrients from other plant matter
in the canopy and transfers it to other areas, sometimes far away. There have
been a number of studies about canopy nutrient cycling in recent years that
describe this process. All of this activity serves to provide suffient levels
of nutrient to epiphyte colonies that sometimes attain massive ecosystems
high above the forest floor. Hemiepipytes want to get up there to tap into
this richness and to join the party!

Hemiepiphytes may also develop other similar root strategies as found in
epiphytes once they leave the ground behind. Leaves, stems and roots of some
species in seasonally dry areas may develop to become very succulent for
storing water. Some of the bird's nest type anthurium may trap debris that
helps to hold moisture and provide extra nutrient. The canopy life is not so
easy however, and can be harsh, much hotter than on the ground. Even in the
rainest areas of the world, epiphytes must endure brief scorching dry periods
more intense than anything encountered on the canopy floor.

Many climbing and/or hemiepiphytic aroids will not flower unless they can
scramble to great heights. Hemiephytes have developed flowering strategies to
utilize different pollinators or seed dispersers that reside high in the
canopy. These agents are perhaps not found on the ground, or the canopy
residents may be more efficient at their tasks than ground dwellers, so the
hemiepiphtye wants to get their flowers up to them. Whatever the case, there
may be a number of compelling reasons why a plant might evolve into a
hemiepiphte rather than stay on the ground where there it can survive more
easily with a steady water supply. Major driving forces for change are those
that promote success in pollination and seed dispersal.

Donna Atwood
Selby Gardens

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From: alan san juan kalim at erols.com> on 2000.05.19 at 21:26:23(4600)
ok, cool. Thanks to those who gave answers.

I note though that most explanations focus on why a plant would want to
get to the canopy area, as opposed to why it would elect to GET RID of
the underlying stem. One writer, who wrote by email, noted that this may
be simply the result of cumulative damage to the lower (and older)
regions of the plant. Although this may be possible, my understanding is
that the degradation is too drastic to be simply due to random
accidental events, and it of course does not address why this would
occur in several diffrent groupings of plants while not in most others.
Indeed, I once observed a large PHilodendron in a greenhouse which clung
only 1.5 meters or so above the ground...its old pot lay forlornly below
it....

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From: Lewandjim at aol.com on 2000.05.20 at 08:13:44(4601)
In a message dated 05/20/2000 12:26:49 AM Eastern Daylight Time,
kalim@erols.com writes:

<< Many plants (I think) do not

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From: "Jay Vannini" interbnk at infovia.com.gt> on 2000.05.20 at 08:15:51(4603)
Alan:

As a lay observer, I don't pretend to have an answer to your question, but
rather will pose another related one - that is - do these "hemiepiphytic"
aroids always dispense with soil root systems once airborne elsewhere in the
Neotropics?

Sorry to jump in so late here with my two centavos worth, but it is my
observation that several of the large scandent aroids that are native to
northern Central America commonly continue with very visible links to the
ground, even as they pursue the good life in the upper canopy. I have
recently examined a vigorous wild population of the species that you first
mentioned (Monstera deliciosa) in premontane wet forest near that Chiapan
border and, offhand, I remember that many of the plants I saw could be
traced back down to the ground down very robust host-clasping stems. This
was also evident in mature Monstera friedrichsthalii, Syngonium steyermarki
(ID?) and a very large Philodendron sp. seen in the same region.

Again, this is only my opinion from admittedly casual observation, but it
seems to me that while these plants CAN readily dispense with ties to the
soil, they don't necessarily have to do so. Therefore, this event seems more
an adaptation to accidental (?) loss of the original root system - clearly
an advantage to plants whose fates would otherwise be tied to that of their
hosts following its death. As anyone who has visited an old light gap caused
by a tree fall in humid tropical forests in this region can attest, many
mature vines attached to fallen trees have often just reverted back to the
juvenile climbing stage and headed for the nearest handy trunk to
re-colonize.

Perhaps we shud refer to this regenerative phase as "phytopragmatism" (just
kidding).

Amongst several other groups of plants that I am familiar with, there are
indeed clear parallels to this habit in some aroids. Several of the larger
"highland" Nepenthes pitcher plants from tropical Asia, most notably N.
lowii and N. pilosa, often part from old, rotting basal stems and continue
to grow and reproduce as epiphytic canopy vines. Likewise, many cereoid
cacti inhabiting moist tropical habitats, esp. Selenicereus testudo,
Hylocereus spp. and Werckleocereus spp. also do this on a regular basis.
Again, this appears to be an adaptive response by succulent-stemmed climbers
to environments conducive to loss of basal stems and roots due to fungal,
bacterial and insect attack over the relatively long life of the plant.

Your questions do open an interesting avenue of research, that is, how
common is this ability in tropical climbers and what species do
"voluntarily" cut ties to the ground, and why. There are a number of
individuals that attend this forum that are familiar with regions with far
higher epiphyte diversity than Guatemala and Mexico; perhaps they will share
their views on this subject.

Best of luck with your project,

Jay Vannini

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From: alan san juan kalim at erols.com> on 2000.05.20 at 20:41:33(4606)
THanks for all answers.

I guess I was premature in assuming that wild populations of some
Philodendrons actually did do this (my MS was in Plant Molecular Bio,
and I now do programming, so I'm definitely not an expert). I had based
my questions on readings and 1-2 specimens that I had studied, but all
were greenhouses specimens and may have been showing altered behavior
from the wild.

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From: Damian Trownson DrPaulBear at xtra.co.nz> on 2000.05.21 at 15:01:40(4608)
alan san juan wrote:
>
> THanks for all answers.
>
> I guess I was premature in assuming that wild populations of some
> Philodendrons actually did do this (my MS was in Plant Molecular Bio,
> and I now do programming, so I'm definitely not an expert). I had based
> my questions on readings and 1-2 specimens that I had studied, but all
> were greenhouses specimens and may have been showing altered behavior
> from the wild.
>
> The behavior seemed so remarkable to me, so I figured I might get some
> answers by posing the questions to this group.
>
> Thanks again.
> alan.
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From: China Syndrome hermine at endangeredspecies.com> on 2000.05.21 at 20:42:27(4609)
>
> >
> > The behavior seemed so remarkable to me, so I figured I might get some
> > answers by posing the questions to this group.
> >
> > Thanks again.
> > alan.
>Whatever else Alan you generated some very interesting discussion,and I
>for one found them informitive and enjoyable. Thankyou .
>Paul

Oh some Ficus does this. sort of. it starts out as an epiphyte and then
puts down long roots into the ground, which duplicate the action of muscle
tissue and contract, ultimately throttling the host. Pulling the Ficus
into the earth. your "strangler fig". now i know this is NOT the
FIGS@egroups.com list, so don't PLEASE yell at me for an off-topic post.
and i also know that this is a plant starting out as an epiphyte and
winding up as a terrestrial, which is backwards of the original question. I
should mention this is different from the contractile roots which pull
certain succulents into the ground in droughts. it actually replicates the
contractile tissue of muscle, it does not merely dry and contract.

hermine

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From: alan san juan kalim at erols.com> on 2000.05.21 at 20:43:33(4610)
just for your info:

I looked up where I got the idea, and here are some references:

(1) Foraging Behaviour in Tropical Herbaceous Climbers (Araceae); Ray,
Thomas S; The Journal of Ecology, Oxford; 1992; Vol. 80, Iss. 2; pg. 189

In the introduction to this article, Thomas notes that some of the
climbers "moved" through the understory and to the canopy using rapidly
growing tips and (final) senescence of the lower stem region.

(2) The HIgh Frontier: EXplring the Trpical Rainforest Canopy, by Mark
MOffett

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From: "Bonaventure W Magrys" magrysbo at shu.edu> on 2000.05.22 at 15:21:54(4615)
Jay,
What about Vanilla vines?
Bonaventure Magrys

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From: Don Burns donburns at macconnect.com> on 2000.05.23 at 14:53:03(4617)
>Date: Tue, 23 May 2000 16:50:02 -0500 (CDT)
>Reply-To: bergh@tpg.com.au
>Originator: aroid-l@mobot.org
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From: "van den Bergh" bergh at tpg.com.au> on 2000.05.23 at 14:54:13(4618)
As a gardener who knows little about the mechanics of plants, I recently
removed the pot under a Selenicereus which had parted company with its base
and root system [due to rot] in the pot and was happily growing up a cement
wall 30cm. from the ground. Do I understand fom your discussions, that this
plant will now keep on growing as it is, attached to the wall, and get
nourishment from the air.
Marilyn van den Bergh.

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From: "Jay Vannini" interbnk at infovia.com.gt> on 2000.05.23 at 19:21:42(4621)
Dear Marilyn:

Depends on the species in my opinion.

Selenicereus (formerly Deamia) testudo is commonly observed to start life
either as an epiphyte or as a seedling that snakes up (in this area) palms
and tropical oaks. Either way, it is unusual to see them "tapped" into the
ground as a mature plant. These cacti, in addition to some members of the
other genera I mentioned appear to "trap" debris with their stems and roots
and are quite successful after having "lost" their original soil root
system. I have a Cuban species, S. cf. inermis that has long since
overflowed out of its basket and many meters up into a tree where some stems
have broken, re-rooted and continued on their way. I emphasize that this is
under "wild" conditions - I am not certain that either a Monstera or a
Selenicereus can duplicate this feat on a well-scrubbed brick wall!

On the Vanilla query by B. Magrys: Vanilla is a fairly large genus with a
pantropical distribution. While V. planifolia and V. pompona (valid?) are
widely cultivated on trellises after growing up from the soil, there are, as
I understand it, a number of smaller spp. that are purely epiphytic in
habit. Does Vanilla planifolia commonly leave its soil root system? Frankly,
I don't know the answer to this.

Kind regards,

Jay

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From: StellrJ at aol.com on 2000.05.23 at 19:27:42(4622)
In a message dated Fri, 19 May 2000 2:55:45 PM Eastern Daylight Time,
SelbyHort@aol.com writes:

<< True epiphytes have a different root structure that allows them to very

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From: StellrJ at aol.com on 2000.05.23 at 19:28:27(4623)
In a message dated Sat, 20 May 2000 12:26:48 AM Eastern Daylight Time, alan
san juan writes:

<< ok, cool. Thanks to those who gave answers.

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From: alan san juan kalim at erols.com> on 2000.05.23 at 20:49:28(4624)
Your mention of fast growing, ground-hugging plants reminds me of
something I read ---- that many Philodendron species, when on the
ground, seek climbing surfaces by rapidly growing in a "stolon"
pattern...with long internodes and very minute leaves. Once a climbing
surface is scaled, the plant structure changes, with much shorter
internodes and larger, elaborate leaves.

I have continued to read up on the subject, and here is another mention
of secondary hemiepiphytes and loss of lower stem portions:

"The second type start their lives on the ground or on tree trunks near
the ground (where they send roots to the ground) and climb trees where
they become adults and may lose their connection with the ground. These
are referred to as secondary hemiepiphytes (Putz & Holbrook, 1986)."

This is from DR. Croat's paper on Philodendrons at:
http://www.aroid.org/genera/Philodendron/habgrowpat.htm

alan.

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From: Jmh98law at aol.com on 2000.05.24 at 14:52:14(4627)
Jay Vannini asked:

<< Does Vanilla planifolia commonly leave its soil root system? >>

I've grown it for ten years, and it's still well connected to its growing

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From: StellrJ at aol.com on 2000.05.25 at 18:40:23(4638)
<< just for your info:

I looked up where I got the idea, and here are some references:

(2) The High Frontier: Exploring the Tropical Rainforest Canopy, by Mark
Moffett

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