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Scientific Name | Tetraena pterocaulis (Van Zyl) Beier & Thulin |
Higher Classification | Dicotyledons |
Family | ZYGOPHYLLACEAE |
Synonyms | Zygophyllum pterocaule Van Zyl |
National Status |
Status and Criteria | Critically Endangered B1ab(iii,v)+2ab(iii,v) |
Assessment Date | 2015/04/24 |
Assessor(s) | L. von Staden |
Justification | A rare, localized species, known from one location (EOO and AOO <1 km²), where it is declining due to ongoing habitat degradation as a result of overgrazing and trampling. It is therefore assessed as Critically Endangered under criterion B. |
Distribution |
Endemism | Not endemic to South Africa |
Provincial distribution | Northern Cape |
Range | This species occurs from Schakalsberg in southern Namibia to Cornellskop in the Richtersveld. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Western Gariep Hills Desert |
Description | Plants grow in limestone-rich, stony soils, on slight slopes and in dry stream beds. |
Threats |
| Severe overgrazing and trampling is causing a loss of vegetation cover, and a decline even in species that are not grazed at the only known location of this species in South Africa. In Namibia it is potentially threatened by habitat destruction (Loots 2005). |
Population |
This species is known from a single location in South Africa, a hill of unique geological composition, and it is possible that this species is restricted to this site. It is also rare in Namibia, where it is known from four to eight locations near the Orange River (Loots 2005). The South African population is declining, but the Namibian population is stable (Loots 2005). The South African population is however isolated, and unlikely to experience significant rescue effects from the Namibian population. Subpopulations are small, and an absence of seedlings and young plants are concerning (Van Zyl and Marais 1999).
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Zygophyllum pterocaule Van Zyl | CR B1ab(iii,v)+2ab(iii,v) | 2015.1 | | Zygophyllum pterocaule Van Zyl | Least Concern | Raimondo et al. (2009) | |
Bibliography |
Beier, B.-A., Chase, M. and Thulin, M. 2003. Phylogenetic relationships and taxonomy of subfamily Zygophylloideae (Zygophyllaceae) based on molecular and morphological data. Plant Systematics and Evolution 240(1-4):11-39.
Loots, S. 2005. Red Data Book of Namibian plants. Southern African Botanical Diversity Network Report 38. SABONET, Pretoria and Windhoek.
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.
Van Zyl, L. 2000. A systematic revision of Zygophyllum (Zygophyllaceae) in the southern African region. Unpublished PhD, University of Stellenbosch, Stellenbosch.
Van Zyl, L. and Marais, E.M. 1999. Three new species of Zygophyllum (Zygophyllaceae) from Namibia and Northern Cape, South Africa. Bothalia 29(2):231-237.
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Citation |
| von Staden, L. 2015. Tetraena pterocaulis (Van Zyl) Beier & Thulin. National Assessment: Red List of South African Plants version . Accessed on 2025/04/14 |
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