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Scientific Name | Enarganthe octonaria (L.Bolus) N.E.Br. |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
Synonyms | Mesembryanthemum octonarium L.Bolus, Ruschia octonaria (L.Bolus) G.D.Rowley |
National Status |
Status and Criteria | Endangered A4ace |
Assessment Date | 2022/06/05 |
Assessor(s) | P.C.V. Van Wyk & D. Raimondo |
Justification | A species endemic to the Richtersveld, with an extent of occurrence (EOO) of 2735 km², it is experiencing rapid population decline in response to drought, habitat loss from mining and habitat degradation from livestock overgrazing. Between 30 and 40% of the population has been lost between 2007 and 2022 and a further 30% is likely to be lost by the year 2050 (generation length 15 years). It therefore qualifies for listing as Endangered under criterion A4. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This species is restricted to the Richtersveld region of the Northern Cape Province, South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Namaqualand Strandveld, Lekkersing Succulent Shrubland, Namaqualand Heuweltjieveld, Western Gariep Hills Desert, Western Gariep Lowland Desert |
Description | It occurs on slopes of quartzite and in river alluvial soils. |
Threats |
| It has lost 50% of its population to the impacts of an extended drought, the worst on record for this region, which started in 2015 and is still ongoing at the time of assessment. Predictions of future climate change include further increases in annual average temperature of between 1.4°C and 2.4°C by 2050, (van Wilgen and Herbst, 2017), thus ongoing losses of mature individuals from the impacts of drought and increased temperatures are expected. This species has also lost habitat to mining operations active along the Orange River Valley. Its habitat has also been degraded by overgrazing and trampling by livestock across its range. |
Population |
A formerly common species, with between 20 and 30 subpopulations recorded, this species has been badly impacted by drought, loss of habitat to mining and ongoing degradation from livestock overgrazing and trampling, and the population is declining rapidly. Based on field surveys undertaken across this species range between 30 and 40% of the population has been lost between 2007 and 2022, and a further 30% loss is suspected to occur over the next 30 years given that areas have been licenced for mining and based on the climate models that predict ongoing aridification and temperature increases.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Enarganthe octonaria (L.Bolus) N.E.Br. | Least Concern | Raimondo et al. (2009) | |
Bibliography |
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.
Snijman, D.A. 2013. Plants of the Greater Cape Floristic Region 2: The extra Cape flora. Strelitzia 30. South African National Biodiversity Institute, Pretoria.
Van Wilgen, N.J. and Herbst, M. 2017. Taking stock of parks in a changing world: The SANParks Global Environmental Change Assessment. SANParks, Cape Town.
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Citation |
| Van Wyk, P.C.V. & Raimondo, D. 2022. Enarganthe octonaria (L.Bolus) N.E.Br. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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