Re: [Aroid-l] Chirality

From: "Ertelt, Jonathan B" <jonathan.ertelt at Vanderbilt.Edu> on 2011.10.31 at 19:17:22(22246) Although I also like Anthurium wendlingeri for the spiraling infloresences, I collected an Anthurium sp. in Costa Rica back in 1992 that I have not yet sent photos to Tom Croat for i.d.ing, but the whole plant spirals as it grows, at least growing on smaller (2-3” diameter) tree trunks. It’s a wonderful species, with more roots growing up and out onto the leaves then grow attaching to the tree trunk host – one of the best non-bird’s nest examples of the trash-basket root system I’ve ever seen. The inflorescence and spathe are both green initially, the spadix slowly going slightly more yellow. The fruits are light orange as they pop out, and somewhat quadrangular at the base. The leaves are wide sword-shaped, to almost two feet long on short petioles – that’s the best I can do without going and looking again at the plant for more detail. I’m doubtful that it’s a new species, though wouldn’t that be neat – but I do plan on taking some detailed pictures and sending them on before long. In any case, a wonderful spiral. Jonathan HTML +More On 10/31/11 10:17 AM, "Christopher Rogers" wrote: Greetings all, 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! 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 plant tag they coil around it. Some stems will then slowly 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. Happy days! Christopher On Wed, Oct 26, 2011 at 11:58 AM, Theodore Held 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 : > 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 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’s 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 “handedness.” >> 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. >> >> _______________________________________________ >> Aroid-L mailing list >> Aroid-L@www.gizmoworks.com >> http://www.gizmoworks.com/mailman/listinfo/aroid-l > _______________________________________________ > Aroid-L mailing list > Aroid-L@www.gizmoworks.com > http://www.gizmoworks.com/mailman/listinfo/aroid-l > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l --_000_CAD45E721032Ejonathanerteltvanderbiltedu_-- --============== 73149550405697807==

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