Stapelia gigantea: stinky time is here again

October 14, 2015: Like every year at this time, the Stapelia gigantea on the front porch is getting ready to flower.

October 16, 2015: The first flower unfurls.

October 17, 2015: Three flowers are now open, and a vaguely unpleasant scent is permeating the air on the front porch. Unpleasant to humans, that is. To flies it’s irresistible, as you can see in the photo below.

The flowers are a magnet for bottle or blow flies. The smell, the hairy surface and the striated markings cause them think these flowers are rotting animal meat. The female flies, in turn, proceed to lay their eggs in the center of the flower. As they do that, pollen sticks to their bodies, which they then transfer to another stapelia flower, effecting pollination.

In the next photo, look for the whitish accumulation in the center of the flower on the left. These are eggs and maggots that have hatched after just one day. In the contrast, the flower on the right, which has just opened up, doesn’t have any eggs yet.

Here is a close-up of the eggs and maggots:

And and even better shot taken with a macro lens:

And if you feel particularly daring, watch this video. It shows the maggots writhing around.

Fly larvae in Stapelia grandiflora from Gerhard Bock on Vimeo.

Since there’s nothing for the maggots to eat, they die pretty quickly, and the spent flower closes up again. Each flower is open for about four days.

Stapelia gigantea is native to southeastern Africa where it forms large clumps up to 6 ft. across.

As you can see in the first photo above, my Stapelia gigantea has pretty much taken over the bistro table on the front porch. As much as I’d to like to move it somewhere else (and reclaim use of the table), it’s happy there. The ventilation from below has helped keep mealy bugs at bay, another plus. So for now I’ll leave it where it is.

My Stapelia gigantea is in the shade 90% of the time and gets maybe an hour of direct sun in the late afternoon. In the spring, fall and summer, I water it once a week, just enough for the excess to start running out of the drain hole, and fertilize it once a month with dilute Miracle-Gro All Purpose Plant Food. In the winter, I don’t water it at all.

My plant is outside all winter, although it’s quite protected on the front porch (temperatures there don’t drop much below freezing). I don’t know what its exact cold tolerance is, but Dave’s Garden says zone 9a (20°F). Personally, I would protect it if temperatures are expected to drop below 25°F.