This is a really nifty study of something completely new, an orchid that gets self-pollinated by rain. Orchids have a funny arrangement where two waxy masses of pollen are spacially separated from the stigma in such a way that it usually takes a pollinator to move pollinia to the stigma. During the rainy season, pollinators may be rare, especially if an insect, so having a mechanism for self-fertilization is an important fail-safe. It wasn't clear in the summary, but TPP guesses that the flower has a period, probably several days, during which it waits patiently to be pollinated, and then as it nears the end of its functional life, it changes so that, as this paper reports, the force of a rain drop hitting the cover over the pollinia releases them, and they spring out and rebound on an elastic strand to land on the stigma. This is very unique. There are quite a few plants that disperse propagules (seeds, plantlets, spore packets) using the force from falling rain drops. But this is the first instance of this for pollination. In several of these cases the fruit wall or a cuplike structure causes the falling drops to forceably rebound. It will be interesting to see if the flower has any such structure. How very cool. HT to AoB Blog.