Milkweed in Flower

Day 271: The milkweed is blooming! The plants bore only a few flowers last year, and while I had hoped that an appropriate pollinator would stop by, no pods ever developed. There will be more opportunity this year, though, because there are many more flowers on plants in two patches. Surely some innocent bug will get a leg trapped long enough to pick up some pollinia. That's how milkweed works. Pollen transfer occurs in sticky packets, not dry grains. A bug's leg gets caught inside a slit in the stigma, wiggles around as the insect tries to free itself, and the sticky pollen packets (which generally occur in pairs) get tangled in the hairs on its leg. The insect then visits another milkweed flower, makes a similar mis-step, gets trapped again, and in its efforts to free itself, the pollinia comes off inside the stigma of the second plant. And it has to be a different plant. Milkweed is not self-fertile. Sidebar: I have seen a video of a botanist attempting to cross-pollinate a rare milkweed. Gives me ideas, that, and I'm sure by now, you know that I enjoy botanical match-making. Anybody thinking there might be an experiment on the horizon? Worth a try, but I might not be able to tell who was the responsible party, me or a bug. Not exactly a controlled experiment, but if I get milkweed pods, I'd be happy. Tweezers...where'd I put the dissecting tweezers?

Milkweed Explorer

Day 254: Last year, my milkweed finally bloomed, but never made pods to set seed. Milkweed isn't pollinated like other plants where loose pollen is transported from one plant to another. Its pollen particles are waxy, and adhere to one another to form masses called pollinia. These can only be accessed through a narrow slit in the side of the stigma. When an insect accidentally gets a leg inside the slit, sometimes a pollinium or two (they occur in pairs) gets caught and extracted. Now comes the tricky part. The insect must now get its leg caught in a slit again, but on another plant, and then if the Pollination Gods are smiling, some of the pollen from the pollinia/pollinium will be left behind. Fortunately for milkweed species, insects aren't too bright, so the chances of getting a foot caught in the same kind of "bear trap" twice are relatively high. Milkweed is pollinated largely by insects, but here there seems to be an arachnid ready to offer a helping hand...I mean, "foot."