Quote:
Originally Posted by Frdemetr
Cj,
"New phenomenon"???? I agree with you, nothing "new" there; interesting, but not new! Cattleya aurantiaca (now "Guarianthe") do the same thing, in some clones the buds never open, the self-pollination happens in a closed room, hidden from curious eyes....
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Well, the sort of cleistogamy exhibited by G. aurantiaca and some other things (some Hexisea) is a result of the tissue between the anther chamber and the stigma withering and allowing stigmatic fluids to contact the pollen still in place within the anther, which then sends it's tubules into the stigmatic cavity and eventually to the ovary. The form of cleistogamy illistrated here involves the tissue that holds the anther cap in place withering, the anther cap falling of, and the caudicles flexing back to place the pollen on the stigmatic surface.
This is, of course an evolutionary response to a lack of a proper pollinator. There are several species in Europe that self-pollinate almost exclusively, despite flowers that *do* open and are cross-fertile with others of the species. Presumably, were the pollinating insects to return, the species could continue apace with normal breeding. Sometimes, however, the need to self-pollinate continues long enough that the buds of some populations (e.g. the Guarianthe aurantiaca mentioned earlier) evolve to the point that the buds never even open and pollination happens with the buds tightly sealed. This is why it is often a disappintment buying wild-collected aurantiacas. You could very well end up with a totally cleistogamous clone. Better to stick to nursery stock.
-Cj
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