This Week's Mystery Plant

Is it a flower or is it an exploded possum? It's an amazing flower: sometimes up to 18 inches across when fully open. Five fleshy petals are fused together, and there is a shallow bowl-like indentation in the middle. In the very center are the reproductive parts, partially hidden from easy view. You can hardly overlook this thing, as it is almost shocking in appearance. The surface of the creamy, reddish or tan petals is barred, sometimes ridged. Along the margins of the petals is a fringe of soft white hairs-- which could remind us of fur. This is a flower that somehow resembles road kill. What's more, the flowers are highly odorous, and not pleasantly: they give off the perfume of a dead animal. The flower's color, texture and odor produced in fact mimic dead critters, and with reason, as they attract and are pollinated by flies.

Our mystery plant comes from southern Africa. It is easy to grow on a patio, potted in coarse, gritty soil. The plants are tender, and need to come indoors in the winter. Lots of people would think that this species (and many of its near relatives) are cacti. Sure enough, the plant body is fleshy and succulent. Each branch is usually equipped with several green ridges, and these ridges often bear soft teeth. No real spines are present, but the plants strongly resemble cacti that you might see in the American Southwest.

The biological situation is this: our mystery species comes from a group of plants that we know as the milkweeds, and these are not at all related to the cactus family. These two families have very different flower structures. The occurrence of two very similar growth "forms", in this case, succulent, water-storing stems without prominent leaves, is largely a phenomenon that biologists call "convergent evolution". In fact, there are several good examples of unrelated plant groups that have adapted similar survival tools based upon their environmental pressures, which in this case arises from a dry, arid habitat. (Photo by Linda Lee.)

Photo by Linda Lee