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Scientific Name | Conophytum saxetanum (N.E.Br.) N.E.Br. |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
Synonyms | Conophytum exiguum N.E.Br., Conophytum graessneri Tischer, Conophytum misellum N.E.Br., Conophytum namibense N.E.Br., Conophytum saxetanum (N.E.Br.) N.E.Br. forma hallianum G.D.Rowley, Conophytum saxetanum (N.E.Br.) N.E.Br. var. misellum (N.E.Br.) Rawé, Conophytum vescum N.E.Br., Mesembryanthemum saxetanum N.E.Br. |
National Status |
Status and Criteria | Endangered A4c |
Assessment Date | 2021/12/07 |
Assessor(s) | A.J. Young, P.G. Desmet, I. Ebrahim, D. Guo, A. Harrower, L. Jabar, L. Knoetze, C. Rodgerson, P.C.V. Van Wyk & N.N. Mhlongo |
Justification | This succulent is endemic to the Karas region of Namibia and the Northern Cape province of South Africa where it has an extent of occurrence (EOO) of 12,038 km² and an area of occupancy (AOO) of 132 km². Anthropogenic climate change is a major threat to this species. Loss of vegetation cover has been observed across its geographic range via Landsat imagery between 1984 and 2018 and is used to infer that the habitat quality is already in decline. Modelling of climate change impacts is predicted to result in an average loss of 84% of suitable bio-climatic habitat by 2080 under likely CO2 emission scenarios (RCP 2.6). However, this species occurs across several vegetation units and is expected to show some resilience to climate change. Thus while model predictions place this taxon in the category Critically Endangered under criterion A, the expected population decline has been reduced by 20% to 64% based on the uncertainty of the response to climate change. This species is also threatened by illegal collection. It therefore qualifies as Endangered under criterion A4. |
Distribution |
Endemism | Not endemic to South Africa |
Provincial distribution | Northern Cape |
Range | This species is primarily known from numerous locations along the Atlantic coast of parts of the Northern Cape province of South Africa but also occurs in Karas region of Namibia. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Desert, Succulent Karoo |
Description | This dwarf succulent is known from the Southern Namib Desert and Namaqualand Sandveld bioregions of the Desert and Succulent Karoo biomes, respectively. The plants are located on rocky areas (shale, gneiss, grey schist, granite or dolomite gravel) where they often occupy cracks and crevices. It is especially prevalent near the Atlantic coast and may receive salt spray. The plants are found at sea-level and at the summits of small hills, often on west- and south-facing slopes in part-shade and in full sun.
This species has a generation length of 30 years. It is expected to be sensitive to the impacts of climate change as it does not disperse and while adapted to arid conditions, is dependent on limited seasonal rainfall. Species in the genus are sensitive to long periods of drought. Drought related mortality has been observed for other closely related taxa within the genus. |
Threats |
| This species is currently threatened by illegal collection for the international trade in ornamental succulents. This is likely to increase in future as there has been a dramatic increase in the number of species and volume of plants targeted since 2019. The distribution of these plants across numerous localities in very remote areas, most of which is restricted in terms of access indicates that the decline due to this activity will be less than 30% of the population.
Anthropogenic climate change is a long-term threat to this species. Loss of vegetation cover has been observed across the geographic range occupied by this species via Landsat imagery between 1984 and 2018 indicating a decline in habitat quality. Climate models for the likely emission scenarios where emissions stay at present day levels (RCP 2.6) (Hausfather and Peters 2020) and worst case scenarios where emissions continue to increase during the 21st century (RCP 8.5) indicate that there will be a loss of suitable bioclimatic envelope of between 84% and 100% by 2080 for this species. However, as this species occurs across several vegetation units it is expected to have a level of resilience to climate change and the expected population loss is reduced by 20% to 64%. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely.
Mining and its associated infrastructure has a localised impact on some subpopulations. |
Population |
This succulent is known from numerous locations where it is typically locally common. There are no formal estimates of population size for this species but there are likely between 200,000 and 300,000 mature individuals. The population is experiencing initial levels of decline due to illegal collection for the international trade in ornamental succulents.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum saxetanum (N.E.Br.) N.E.Br. | Least Concern | Raimondo et al. (2009) | |
Bibliography |
Hammer, S. 2002. Dumpling and his wife: New view of the genus Conophytum. EAE Creative Colour, Norwich.
Hammer, S.A. 1993. The genus Conophytum: A conograph. Succulent Plant Publications, Pretoria.
Hausfather, Z. and Peters, G.P. 2020. Emissions - the 'business as usual' story is misleading. Nature 577(618-620).
Opel, M.R. 2004. The rediscovery of Crassula alcicornis. Haseltonia 10:38-40.
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Citation |
| Young, A.J., Desmet, P.G., Ebrahim, I., Guo, D., Harrower, A., Jabar, L., Knoetze, L., Rodgerson, C., Van Wyk, P.C.V. & Mhlongo, N.N. 2021. Conophytum saxetanum (N.E.Br.) N.E.Br. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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