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  Re: [Aroid-l] Chirality
From: Christopher Rogers <branchiopod at gmail.com> on 2011.10.31 at 15:17:04
Greetings all,
=A0
I agree with Leland: Anth. wendlingeri is also my favorite aroid that spirals. When I had that plant prior to my move, I had many blooms, but I do not recall if the inflorescences all spiraled in the same direction or not. However, there was one bloom that started spiraling one way, then changed and spiralled the opposite direction!
=A0
Add to this my second favorite group of plants (after the aroids): Utricularia, the bladderworts. I used to grow U. prehensilis. This terrestrial species sends out long stems from the soil surface that tend to stick out at close to 45 degrees from the horizon. Over the course of the day they slowly swing in an arc. I the encounter a stem of another plant or a=A0plant tag they coil around it. Some stems will then=A0slowly uncoil and swing back in the opposite direction, again until the encounter an object, and again, they coil around it. So, here is an example of a plant that will coil both directions on the same stem.
=A0
Happy days!
Christopher

On Wed, Oct 26, 2011 at 11:58 AM, Theodore Held <oppenhauser2001@gmail.com> wrote:
List:

Ah, good. That means I'm not the only one to observe this sort of
growth pattern. To tell the truth, it seems to me that different
handedness might be more common than I thought, but the phenomenon is
not something one might notice, even with two specimens side-by-side.

Not being a botanist, my first guess is that there is some sort of
tiny 'kick', probably hormonal or environmental, that happens to a
meristem early in the development of a leaf or inflorescence, which is
then carried on without further chemical influence as the cells go
about their assigned roles.

In vining plants, there are some species that ALWAYS curl to the right
and others that ALWAYS curl to the left. So sometimes it is not merely
random. Offhand I cannot think of any special advantage one twist
direction might give to an aroid. Of course, in vining species I can't
think of any special advantage either; and yet they do it faithfully.

Ted Held.

2011/10/25 Kathy <ku5@yahoo.com>:
> About "handedness" with aroids, Ted: when the spathe of Amorph titanum unwraps and opens it's easy to observe this, and all the ones that have flowered for me have been left handed, and all the ones at University of Wisconsin have been right handed. I don't know the reason for this, but it's interesting.
>
> Sent from my iPhone
>
> On Oct 24, 2011, at 12:46 PM, Theodore Held <oppenhauser2001@gmail.com> wrote:
>
>> Dear List,
>>
>> Attached here (with luck) is a picture I made of a pair of blooms from
>> a Cryptocoryne griffithi (identity confirmed by Peter Boyce at the
>> recent IAS show). What=92s interesting to me is that the outer spathe
>> tip (called the flag for Crypts) of the plants twists to the left for
>> one and to the right for the other. These plants are vegetative kin.
>>
>> I have also seen the pairing of left-handed and right-handed
>> inflorescences on Cryptocoryne pontederifolia.
>>
>> Has anyone ever noticed mirror-image flower forms like this with any
>> other aroids? In chemistry differences involving only mirror images
>> are referred to as chiral isomers and originate with subtle
>> molecular-level geometry. In normal life this is called =93handedness.=94
>> In a plant bloom, the differences may display as macroscopic
>> phenomena, but likely originate with early development, also perhaps
>> on a molecular level.
>>
>> Please enlighten me if anyone knows about this oddity.
>>
>> Ted Held.
>> <IMG_2017.jpg>
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--
D. Christopher Rogers
((,///////////=3D=3D=3D=3D=3D=3D=3D<
785.864.1714
Crustacean Taxonomist and Ecologist
Kansas Biological Survey
Kansas University, Higuchi Hall
2101 Constant Avenue, Lawrence, KS 66047-3759 USA

Associate Editor, Journal of Crustacean Biology http://web.vims.edu/tcs/?svr=3Dwww

Vice President, Southwest Association of Freshwater Invertebrate Taxonomists SAFIT.ORG

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