Beautiful Flowers That Draw Flies

Stapelia flavopurpurea is from Namibia, Botswana and the Northern Cape of South Africa. (SHNS photo courtesy Shoal Creek Succulents)

This family of succulents is indeed Mother Nature's twisted humor at its finest. The joke is the Asclepiad's fascinating relationship to its primary pollinators. The reason is they come from southern Africa, where predator and prey ensure plenty of fresh kills. The kills draw many species of flies, which lay their eggs in the flesh. These hatch out into maggots, which do their part in cleaning up the leftovers. The Asclepiads evolved flowers that exploit this abundance of insect pollen vectors.

I grew a few as house plants in a south-facing window. I never noticed any odor, probably too subtle for the human nose, but houseflies tended to congregate in that window when the plants bloomed. This housefly roundup made it convenient to swat them all at once rather than roaming the house after strays. Clearly Asclepiads can work for you, too.

The waxy starfish-like flowers are called the orchids of the succulent world because of their exotic coloration and unique insect relationship. The stiff, waxy blooms can be puss yellow with brown spots, bloodclot red or aged beef purple. Some have hairs that actually vibrate in still air, perhaps to signal the presence of maggots to passing flies. A female fly can be so taken by this mimicry that she lays her eggs in the flower, believing it a food source for the soon to hatch larvae. But the joke's on the fly because the offspring die of starvation. Plant geeks will want to read the more detailed account of this fascinating pollination process by Gerald S. Barad, M.D, at www.cactus-mall.com/stapeliad.pollin.html

The most spectacular genera of Asclepiads for garden or potted plants are Orbea, Huernia and Stapelia. To see them in sharp color, log on to Shoal Creek Succulents, www.shoalcreeksucculents.com. Check out striped Heurnia zebrina, unscented Orbea longidens, spotted Orbea variegata and fuzzy Stapelia grandiflora.

These and other species of these genera produce attractive flowers, some quite small and others nearly the size of a mayonnaise jar lid. In cultivation the plants thrive under much the same arid conditions as Africa with moderate light, minimal water and absence of frost. Their chief enemy, as with most succulents, is too much moisture.

This is the result of watering too frequently or standard potting soil. Use only cactus potting soil. This ensures it stays light and airy, and won't pack down tight. Water flies straight through it making over-watering practically impossible. Shallow pots are the best because these plants don't have deep root systems. The growth habit tends to crawl along the ground, often rooting as the plant travels, so lots of surface soil area is important.

Bonsai pots, clay cactus trays and dish garden bowls all share abnormally large drain holes. Cover the hole with some nylon window screen to keep the soil from falling through without inhibiting drainage.

It's easy to get started with carrion flowers thanks to Shoal Creek Succulents, the first online mail order nursery to offer an exhaustive range of genera. In the past Asclepiads were few and far between. This source offers plants at a mere five bucks each, which makes it affordable to get started with minimal guesswork.

Even if you aren't a plant geek, these often-overlooked succulents will be as fabulous in a New York apartment window sill as they are in the wilds of Africa.

(Maureen Gilmer is a horticulturist and host of Weekend Gardening on DIY-Do It Yourself Network. E-mail her at mo@moplants.com. For more information, visit www.moplants.com or www.DIYNetwork.com. Distributed by Scripps Howard News Service.)