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  Anchomanes ID, root quest.
From: Neil Carroll <zzamia at hargray.com> on 1999.04.05 at 13:08:20(3234)
Hey aroiders, Two questions as follows:

A couple years ago I bought a couple of Anchomanes... 2 A. hookeri and 2 A.
welwitschii. My problem is this, only one label was sent for each species
and the labels were jumbled in the box when they came. I stuck the two
labels into two of the four pots. OK so far? Well now they are coming out
of dormancy and I have put the two different labels into two pots of the
same species. So this is a which is which question.

One Anchomanes has now leafed out and the other species leaf blade is still
curled tight. But here is the difference. The species that is already
leafed out has a glaucus bloom on the petiole. The other species petiole
has no bloom on it. I hope this is enough for an ID between these two
species. If not I will wait till the leaf completely unfurls and go from
there.

+More
From: hermine <hermine at endangeredspecies.com> on 1999.04.05 at 13:38:48(3236)
>
>I am having an argument on another list. Can anyone help me? I have never
>heard of any plant anywhere that has roots that could be considered
>phototropic. Is this a correct assumption??

YOU TOO? i think never is a very long time, and i too have grown many
epiphytic plants, plants in baskets, and so-called normal plants, if
Sansevierias can be called normal. stoloniferous roots will grow UP out of
the soil, and will re-emerge even if you repot the plant with the roots
buried. the underground roots of bamboo will make croquet wickets. maybe
they are underground stems and not roots as such. when i had epiphytes, i
enjoyed the roots greatly and looked at them long and hard, and i cannot
say they grew away from the light. orchid roots grew in same direction as
the green stuff. ALSO, why would the Machine Who Built The Universe make
roots capable of developing chlorophyll and doing the photosynthetic dance?

This is an oversimplification, but I do not believe roots are ONLY
geotropic, and i bet i could induce roots to grow towards the light if that
is where the water was.

And what about aquatic plants? and why would coralloid roots have a
symbiotic relationship with algae if they were not light-adapted roots?

years ago the cactus and succulent growers did not like white pots as they
allowed too much light into the soil and this did SOMETHING to the roots,
but I cannot remember what it was. However, when i had those plants, i used
white pots, because I had them around, as well as black pots, and I
observed NO DIFFERENCE in the growth.

And then there is growing potatoes and yams in water.

so i do not think the secret of roots is fully grokked.

with unspeakable humble humility, i remain,

hermine

+More
From: "Julius Boos" <ju-bo at email.msn.com> on 1999.04.06 at 06:48:30(3237)
>
>I am having an argument on another list. Can anyone help me? I have never
>heard of any plant anywhere that has roots that could be considered
>phototropic. Is this a correct assumption??

And the 'Ghost Orchid' of our Everglades that lacks any leaves, but the
roots are greenish and lie flat on the growing medium, and puts out and
impressive set of blooms???
Good growing,
Cheers,
Julius

From: Lewandjim at aol.com on 1999.04.06 at 06:52:39(3238)
In a message dated 4/5/99 4:38:36 PM Eastern Daylight Time,
hermine@endangeredspecies.com writes:

<< >I am having an argument on another list. Can anyone help me? I have never

+More
From: Jonathan Ertelt <jonathan.ertelt at vanderbilt.edu> on 1999.04.06 at 14:25:08(3240)
At 3:11 PM -0500 4/5/99, Neil Carroll wrote:

>Second question...
>
>I am having an argument on another list. Can anyone help me? I have never
>heard of any plant anywhere that has roots that could be considered
>phototropic. Is this a correct assumption??
>
Neil,

I believe that you are correct that there are no roots acting through
phototropism. I don't think that roots which are responding negatively to
gravity (I forget the term, but essentially anti-geotropic) as many orchids
and some aroids, especially bird's-nest Anthurioum spp. do, in order to
fashion a trash-basket root system, could be called phototropic. I haven't
seen any studies done, nor noted any growth which would indicate that this
is the response. Neither would luring roots with water towards a light
source work for calling the roots phototropic.
One would expect to see this especially with epiphytes, even more
especially with leafless epiphytes, as has been mentioned, but that is not
what you see - rather, the roots are generally following a moisture
gradient. True, when moist, the roots will green up and become a
photosynthetic organ, but moisture is key here, not light.
Other examples of roots or root structures (which lets go the potato, a
stem) which become photosynthetic upon exposure to light do not then
continue to grow toward the light - at least I've seen no examples of this,
and plenty where it is not what happens.
Likely it is true we do not fully understand roots, or any other plant
structure as fully as we can, but from all the evidence and suggested
evidence presented, I think that you are correct in your assumption.

- Jonathan Ertelt

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