Taxonomy
Scientific Name
Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl.
Higher Classification
Dicotyledons
Family
RUTACEAE
Synonyms
Diosma orbicularis Thunb., Hartogia orbicularis Kuntze
National Status
Status and Criteria
Critically Endangered B1ab(iii)+2ab(iii); C2a(ii)
Assessment Date
2010/11/26
Assessor(s)
T. Trinder-Smith, N.A. Helme, A. Hanekom, I. Ebrahim & D. Raimondo
Justification
This species was not seen at one known location on the Caledon Swartberg since 1932, and was thought extinct due to alien plant invasion, urban expansion and inappropriate fire management. A small subpopulation of 150-300 mature individuals was rediscovered in August 2008. This subpopulation occurs in a 0.1 ha road reserve and is declining due to habitat degradation as a result of invasive alien plants.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Caledon.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Greyton Shale Fynbos
Description
Black manganese rich laterite.
Threats
Threatened by invasive alien species including pines, black wattle and gums, and road verge clearing. Two plants were lost recently due to roadside mowing (A. Hanekom, pers. obs.) It is also threatened by potential future widening and road maintenance of the N2 highway, and mining/extraction of manganese.
Population

Agathosma orbicularis was known since its discovery from a small area to the north of the town of Caledon. A population monitored by a local conservation authority in the 1970s went extinct by 1980. The species was rediscovered in the same area in 2008 and is currently known from a single small subpopulation of less than 300 mature individuals confined to a 0.1 ha road reserve.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl.CR DRaimondo et al. (2009)
Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl.VU D2Victor (2002)
Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl.Endangered Hilton-Taylor (1996)
Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl.Indeterminate Hall et al. (1980)
Bibliography

Bolus Herbarium. The genus Agathosma, specimen data from the Bolus Herbarium Collections database. University of Cape Town, Cape Town. Downloaded on 2007.


Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.


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.


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
Trinder-Smith, T., Helme, N.A., Hanekom, A., Ebrahim, I. & Raimondo, D. 2010. Agathosma orbicularis (Thunb.) Bartl. & H.L.Wendl. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2022/01/25

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Distribution map

© N.A. Helme


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