Dr. T. Ombrello - UCC Biology Department

CARRION PLANTS

Common names: Carrion Plant, Carrion Flower, Starfish Flower

Scientific name: Stapelia species

Explanation of scientific name:

Stapelia - named for J.B.VanStapel, a 16th century Dutch physician

There are 90 species of Carrion Plants that belong to the genus Stapelia. Stapelias, in turn, belong to the plant family Asclepiadaceae (the Milkweed family – named after Asclepias, the common milkweeds).

Native to South Africa, the Stapelias are stem succulents with thick, fleshy, soft, 4-sided stems that are leafless except for some minute scaly bristles. Carrion Plants bear a superficial resemblance to cacti, but are botanically unrelated because of their different floral anatomy. Cacti, incidentally, are native only to the American continents. Stapelias and cacti look quite alike, however, since they evolved over millions of years in similar desert-like environments. They faced the same environmental challenges, and developed adaptations to cope with them. Both groups can withstand long periods of drought because of their ability to store water in their stems. When two unrelated species evolve to appear so similar, biologists label the phenomenon “convergent evolution”.

Probably the most interesting feature of the Carrion Plants is the flower structure. Ranging in size from a fraction of an inch to over 12 inches across, the flowers are 5 – pointed and resemble the starfish of the sea. This resemblance has led to the use of the common name Starfish Flower. The flowers are not pollinated in the usual ways, such as by bees or wind. Instead, flies are the exclusive pollinators. In an effort to attract the flies, Carrion Plants have evolved to produce flowers with properties quite attractive to flies. The odor emitted from these flowers is strong and fetid, resembling that which would come from a decaying animal carcass. In addition to the rank odor, the colors of Stapelia flowers are shades of purple-brown and yellow with striations (bars) of darker colors. This gives the impression of exposed flesh. The fine hairs that cover the surface of the flowers further enhance the resemblance to carrion. Carrion Plant and Carrion Flower are truly appropriate common names.

Even when far from their homeland, the plants attract flies for pollination. When the Stapelia plants bloom in Union County College’s greenhouses, numerous houseflies and blowflies are attracted to and land on the flowers. They appear to be mesmerized while there, since they can often be touched without their flying away. Carrion Plants produce flowers several times a year in Union County College’s greenhouses, with each flower remaining open for at most several days. When not blooming the plants are completely odorless, but when even one flower is open the odor is obvious as soon as the greenhouse is entered. Stapelias are easy to grow as houseplants, if they are not over watered. They can be put outdoors for the summer, as long as they are brought back in before temperatures approach freezing.