Oxalis disticha

Taxonomy
Scientific Name
Oxalis disticha Jacq.
Higher Classification
Dicotyledons
Family
OXALIDACEAE
National Status
Status and Criteria
Near Threatened B2ab(iii,v)
Assessment Date
2016/08/04
Assessor(s)
L. von Staden
Justification
A widespread (EOO 20 128 km²), but highly localized habitat specialist (AOO <50 km²). It is still fairly common in spite of widespread, ongoing habitat degradation, estimated to occur at between five and 10 locations, but is likely to continue to decline.
Distribution
Endemism
South African endemic
Provincial distribution
Northern Cape, Western Cape
Range
Bokkeveld Escarpment to Mamre.
Habitat and Ecology
Major system
Freshwater
Major habitats
Fynbos, Succulent Karoo
Description
Seasonal pools and pans on clay soils, rarely in sandy soils in streambeds. Plants are often floating in standing water.
Threats
Areas surrounding this species habitat is extensively cultivated, however, seasonal pools are not generally ploughed, except in a few instances where pools have been filled in. The most severe causes of degradation of vernal pools in the Western Cape and on the Bokkeveld Escarpment is heavy overstocking with livestock, which leads to overgrazing and trampling of sensitive wetland systems, as well as eutrophication due to fertilizer runoff, which is aiding the spread of alien invasive grasses. Dense alien grass infestations are outcompeting native species in many wetland systems. None of this species' habitat is currently formally protected.
Population

This species occurs in isolated, scattered subpopulations confined to suitable habitat. It is however locally abundant, and subpopulations are large. It is currently known from nine existing subpopulations, and many recent records indicate that it is still fairly common in spite of extensive habitat loss and degradation.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Oxalis disticha Jacq.Least Concern Raimondo et al. (2009)
Bibliography

Cook, C.D.K. 2004. Aquatic and wetland plants of southern Africa. Backhuys Publishers, Leiden, The Netherlands.


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.


Manning, J.C. and Goldblatt, P. 2012. Plants of the Greater Cape Floristic Region 1: The Core Cape Flora. Strelitzia 29. South African National Biodiversity 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.


Salter, T.M. 1944. The genus Oxalis in South Africa: a taxonomic revision. Journal of South African Botany Supplement 1:1-355.


Sieben, E.J.J. 2009. The status and distribution of vascular plants (Magnoliophyta, Lycophyta, Pteridophyta). In: W.R.T. Darwall, K.G. Smith, D. Tweddle and P. Skelton (eds.), The status and distribution of freshwater biodiversity in southern Africa (pp. 83-98), IUCN and SAIAB, Gland, Switzerland and Grahamstown, South Africa.


Citation
von Staden, L. 2016. Oxalis disticha Jacq. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2017/04/26

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Distribution map

© N.A. Helme

© C. Paterson-Jones


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