Stapelia
Stapelia (family Apocynaceae, subfamily Asclepiadoideae) is a group of stem-succulent plants native to southern Africa. These plants are known for producing large, fleshy, star-shaped flowers that often mimic the appearance and scent of rotting meat.
Key scientific features:
• Morphology:
Stapelia plants lack true leaves and instead have photosynthetic, four-angled or cylindrical stems adapted for arid environments.
The flowers typically have five lobes, covered with trichomes (fine hairs) that give them a furry or velvety texture.
• Odour chemistry:
Many species release volatile compounds like putrescine and cadaverine, which create a corpse-like smell.
This odour attracts carrion flies (Diptera)—their natural pollinators. This pollination strategy is called sapromyiophily.
• Pollination mechanism:
Stapelia flowers have a complex gynostegium (a fused structure of male and female organs), typical of milkweed relatives.
Flies get trapped or guided into the flower where pollinia (pollen packets) attach to their limbs. When the fly visits another flower, the pollinia transfer, enabling fertilization.
• Ecology:
They are adapted to semi-desert and rocky habitats, storing water in their stems and opening large flowers only when environmental conditions are favourable.
• Famous species:
– Stapelia gigantea — produces huge flowers up to 35 cm across, pale yellow with reddish lines.
– Stapelia hirsuta — covered in long hairs, strongly carrion-scented.
– Stapelia grandiflora — deep red, leathery, very striking.
• Cultivation note:
They are popular ornamental succulents because they are drought-tolerant, but when they flower, many people are surprised by the strong corpse smell.