This newly described species differs from most yams in its shrub-like form and huge, slow-growing, woody tubers, which form above ground and can reach one metre in both height and diameter.
This, and a related species of yam, are used to treat cancer patients in Mpumalanga, South Africa – the only place it is known to grow – although its efficacy is unknown. Its high levels of steroidal compounds also make it desirable for reduction of inflammation in arthritis. Only 200 plants are known to exist, making this new species also critically endangered. More than half of the tubers of 66% of the known specimens have been harvested. A conservation effort is under way.
Quentin Wheeler is director of the International Institute for Species Exploration, Arizona State University
