Taxonomy
Scientific Name
Oxalis duriuscula Schltr.
Higher Classification
Dicotyledons
Family
OXALIDACEAE
National Status
Status and Criteria
Endangered B2ab(ii,iii,iv,v)
Assessment Date
2020/02/12
Assessor(s)
N.A. Helme, D. Raimondo & L. von Staden
Justification
A range-restricted species (EOO 5062 km²), with a severely fragmented population after more than 80% habitat loss to crop cultivation. It continues to decline due to ongoing habitat loss and degradation.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Overberg between Bot River, Heidelberg and Bredasdorp.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Eastern Ruens Shale Renosterveld, Central Ruens Shale Renosterveld, Western Ruens Shale Renosterveld, Ruens Silcrete Renosterveld, Greyton Shale Fynbos, Elim Ferricrete Fynbos
Description
Renosterveld on sandy flats, 100-500 m.
Threats
This species has lost more than 80% of its habitat to crop cultivation across the Overberg, and loss continues. Subpopulations persist on isolated renosterveld remnants, where they are threatened by competition from alien invasive plants, overgrazing and inappropriate fire management.
Population

This species remains on 12 isolated fragments, and subpopulations are small. Rapid, ongoing habitat loss has been recorded between 1990 and 2014, and recently part of one subpopulation was lost to urban expansion on the outskirts of Caledon.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Oxalis duriuscula Schltr.NT B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)Raimondo et al. (2009)
Oxalis duriuscula Schltr.Insufficiently Known Hilton-Taylor (1996)
Oxalis duriuscula Schltr.Uncertain Hall et al. (1980)
Bibliography

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.


Citation
Helme, N.A., Raimondo, D. & von Staden, L. 2020. Oxalis duriuscula Schltr. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/07/10

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Distribution map

© N.A. Helme


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