Conservation
Dioscorea strydomiana male flowers in axillary racemes and leaves, showing their shape and habit © John Burrows
The most recent field survey of the area where Dioscorea strydomiana grows revealed that there are two populations of this species, each with about 100 plants.
The main threats to the species, after collection of tuber material for use in medicine, are:
- burning
- mining
- cattle farming
- firewood collection
- porcupine activity
- removal of plants for the horticultural trade
Dioscorea strydomiana is thought to be slow-growing and hence slow to recover from damage.
Dioecy means that only the female plants in each population produce seeds - its reproductive potential is therefore limited.
It has been rated as critically endangered according to International Union for the Conservation of Nature (IUCN) Red List criteria.
Measures already taken to protect the species include careful monitoring by members of the Mpumalanga Tourism and Parks Authority, the South African National Biodiversity Institute and the Mpumalanga Plant Specialist Group.
These groups believe the populations of this species are declining at an alarming rate, and they have called for urgent measures to promote the sustainable use and conservation of Dioscorea strydomiana.
The area in which the species grows is not yet a protected area, but is being monitored by the local tribal authority in collaboration with the Mpumalanga Tourism and Parks Authority in an attempt to prevent unscrupulous and illegal collection of plant material.
An attempt to set up a community-run nursery in the local area to provide cultivated plants for the medicinal and horticultural trade was unsuccessful, but collections of seed-grown individuals have been successfully established in 2 of the South African National Biodiversity Institute's national botanical gardens.
Dioscorea strydomiana seeds have been banked at the Royal Botanic Gardens, Kew Millennium Seed Bank.
