An Excerpt from Jim Conrad's
Naturalist Newsletter of January 19, 2009
issued from the Yucat√°n, MEXICO


At "Flamingo Lake" I wanted to see the birds, but there was also one particular plant I wanted to look for, having noticed it during my last visit several years ago. You can see it, with the lagoon in the background and high-rises on the coast of the type destroying so much critical habitat in the area, below:


The plant is about eight feet tall and has woody stems so it looks like Common Milkweed on steroids, right? It is indeed a member of the Milkweed Family, and you can see its milkweed-like flowers (but much larger) below:


This is one of two or more plants called Giant Milkweed. It's CALOTROPIS PROCERA, native from West Tropical Africa to India, but gone wild throughout much of the world's tropics, where it thrives on arid coasts and is impervious to salt spray and wind. Its stem produces a strong fiber for string-making and many cultures use it in folk medicine. It makes a softball-size, bladdery fruit full of white floss of the kind you've probably seen atop milkweed seeds.

Often we've referred to the unusually complex and beautiful anatomy of Milkweed-Family flowers, and Calotropis's flowers are characteristically worthy of taking a close look at, as we do in the close-up below:

Giant Milkweed, CALOTROPIS PROCERA, flower

You may want to refresh your memory about milkweed flowers -- their horns, coronas, pollinia -- at

Our flower's anatomy is a bit different from the milkweeds' at that link -- it's a different genus, after all. I don't have an expert's description of the flower's anatomy but it looks to me as if the blossom's coronas and horns are merged. The pollinarium gland seems to be in place, and one assumes that two pollinia are attached to it below, forming the V-shaped pollinarium shown on the milkweed page.

I was surprised no one had cut down this interesting plant but I was glad they hadn't, despite it's being an invasive. It's a tough plant, and if the predictions of global warming are correct, eventually we'll need all the tough plants we have to hold soil and photosynthesize, no matter where they come from.