reproductive biology of orchids question
OK... so I'll take the risk of showing my ignorance here. It's been
over 20 years since college, but this question came to mind when I
couldn't sleep the other night.
Orchids produce very large numbers of very small seeds. Is each seed
the result of an individual pollination/fertilization event?
Does the one pollen grain, one ovule, one seed rule apply? Do
"multiple maternal twins", for the lack of a better term, occur in the
plant kingdom? (I believe reduction of seeds occurs, but does
multiplication occur as well?)
With the simplicity of orchid seeds, is it possible that more seeds
are produced than pollen grains involved?
Is this a biological rule that is occationally broken, but you never
hear about it in Botany class? If so, what other plants reproduce in
It would seem that the number of pollen tubes necessary to result in
the massive number of seeds produced would destroy the integrity of
the stigma, style, and ovary.
Also, when orchids are pollinated, can more than one pollinia be
involved? Does the presence of one pollinia (pollinium?) exclude
further pollinia? How many pollen grains can be contained in an orchid
This may differ from species to species, but does anyone know?
Can similar trends be found in other plants that produce pollinia,
such as milkweeds? What other plants produce pollinia?
Again, I claim ignorance in this matter... but also express curiosity.
Amazing the things that will bounce around in the brain when you