Drimia oliverorum

Taxonomy
Scientific Name
Drimia oliverorum J.C.Manning
Higher Classification
Monocotyledons
Family
HYACINTHACEAE
National Status
Status and Criteria
Critically Endangered A3c; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)
Assessment Date
2022/08/14
Assessor(s)
P.C.V. Van Wyk, N.A. Helme & D. Raimondo
Justification
This species is only known from one location in South Africa, where it is highly threatened by habitat loss to mining. Given that mining has started in the immediate area adjacent to the subpopulation at the time of assessment, this species is predicted to be regionally extinct within the next five years. With an extent of occurrence (EOO) and area of occupancy (AOO) of only 4 km² it qualifies for listing as Critically Endangered under criteria A and B. While it is known from three other subpopulations in southern Namibia no rescue effect from the Namibia population will be possible since the only suitable habitat is being lost mining.
Distribution
Endemism
Not endemic to South Africa
Provincial distribution
Northern Cape
Range
This species has a restricted distribution in the Northern Cape Province, South Africa, where it is known only from the Gariep Valley. It also occurs in southern Namibia from the Huib Hoch Plateau and near Ai-Ais.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Western Gariep Hills Desert
Description
It grows on stony flats and gravelly patches on quartz outcrop, on alluvial deposits.
Threats
Diamond mining is a severe threat to this species with the only known location in South Africa occurring within the mining footprint of the Lower Orange River mining operation. Mining of this location has started in 2022 and either the only alluvial deposit where this species occurs in South Africa will be mined away or the impacts of mining happening adjacent to the subpopulation will result in dust and silt deposits that will cause the subpopulation to be lost. Threats to the three subpopulations in Namibia are not known.
Population

The only known subpopulation in South Africa is declining due to the impacts of mining and this entire subpopulation will be lost in the next 5 years. Search and rescue actions are currently underway by the South African National Parks (SANPARKS) to ensure ex situ material is available for this species. There is nothing known about the status of Namibia's subpopulations as these have not been recently monitored.


Population trend
Decreasing
Bibliography

Manning, J.C. and Goldblatt, P. 2018. Systematics of Drimia Jacq. (Hyacinthaceae: Urgineoideae) in southern Africa. Strelitzia 40. South African National Biodiversity Institute, Pretoria.


Citation
Van Wyk, P.C.V., Helme, N.A. & Raimondo, D. 2022. Drimia oliverorum J.C.Manning. National Assessment: Red List of South African Plants version . Accessed on 2024/05/20

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Distribution map


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