Taxonomy
Scientific Name
Gerrardanthus tomentosus Hook.f.
Higher Classification
Dicotyledons
Family
CUCURBITACEAE
National Status
Status and Criteria
Vulnerable D1+2
Assessment Date
2007/05/15
Assessor(s)
D. Styles, C.R. Scott-Shaw, D. Raimondo & L. von Staden
Justification
The distribution of this rare species is entirely confined within the Greater Durban Metropolitan Area, one of the fastest developing urban regions in South Africa. It has however survived extensive urban expansion and land degradation by virtue of its inaccessible habitat which is unsuitable for either development or agriculture. It is known from five sites and is potentially threatened by alien plant invasion, habitat degradation due to firewood harvesting and harvesting for medicinal purposes. We estimate that there are fewer than 1000 mature individuals.
Distribution
Endemism
South African endemic
Provincial distribution
KwaZulu-Natal
Range
Durban.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Eastern Valley Bushveld, Northern Coastal Forest, Scarp Forest
Description
Among boulders and screes in steep, wooded, sandstone ravines, 100-400 m.
Threats
The habitat of this species, being quite inaccessible and unsuitable for development, resulted in this species being fairly well protected from the urban spread, agriculture and land degradation of the surrounding Durban Metropolitan area. At one site, harvesting of firewood from the woody ravine where this plant grows is taking place, which may change the structure of the habitat in the long term, and the small population at this site will have to be monitored to detect whether these changes will have an impact. At least one other known subpopulation grows in an area infested by invasive alien species, but as it prefers a shady wooded habitat, it is not known whether this will affect this species. The population needs to be revisited to determine whether it has been declining since 1999. Overall populations appear to be stable and not threatened seriously in any way. A close relative, Gerrardanthus macrorhizus, is harvested for medicinal use. Surveys of the Durban markets over a number of years have not yielded this species (Crouch et al. 1999) and harvesting for medicinal use is not considered a serious threat. It may be occasionally harvested when mistaken for G. macrorhizus.
Population
Population trend
Stable
Conservation
Protected in the Kranzkloof Nature Reserve.
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Gerrardanthus tomentosus Hook.f.VU D1+2Raimondo et al. (2009)
Gerrardanthus tomentosus Hook.f.VU B1B2bcD2Victor (2002)
Gerrardanthus tomentosus Hook.f.VU Scott-Shaw (1999)
Gerrardanthus tomentosus Hook.f.Rare Hilton-Taylor (1996)
Gerrardanthus tomentosus Hook.f.Rare Hall et al. (1980)
Bibliography

Crouch, N., Prentice, C., Smith, G.F. and Symmonds, R. 1999. South Africa's rarest caudiciform cucurbit, Gerrardanthus tomentosus. Bradleya 17:95-100.


Crouch, N.R., Smith, G.F., Symmonds, R. and Condy, G. 2003. Gerrardanthus tomentosus. Flowering Plants of Africa 58:134-142.


Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.


Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.


Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.


Scott-Shaw, C.R. 1999. Rare and threatened plants of KwaZulu-Natal and neighbouring regions. KwaZulu-Natal Nature Conservation Service, Pietermaritzburg.


Styles, D. 2004. John Medley Wood's Inanda - What does it look like today? Part I: The Inanda Valley. PlantLife 30:28-35.


Victor, J.E. 2002. South Africa. In: J.S. Golding (ed), Southern African plant Red Data Lists. Southern African Botanical Diversity Network Report 14 (pp. 93-120), SABONET, Pretoria.


Citation
Styles, D., Scott-Shaw, C.R., Raimondo, D. & von Staden, L. 2007. Gerrardanthus tomentosus Hook.f. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2024/02/29

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Distribution map

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© G. Nichols

© G. Nichols


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