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Scientific Name | Conophytum obscurum N.E.Br. subsp. barbatum (L.Bolus) S.A.Hammer |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
Synonyms | Conophytum barbatum L.Bolus |
National Status |
Status and Criteria | Critically Endangered A3d; B1ab(iii)+2ab(iii) |
Assessment Date | 2021/12/01 |
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 Northern Cape province of South Africa where it is only recorded from a single location with an extent of occurrence (EOO) and area of occupancy (AOO) of 8 km2. It is experiencing ongoing decline in habitat quality as a result of an extended drought which started in 2016 and is ongoing at the time of assessment. The dwarf succulents that comprise this genus have been increasingly targeted by illegal collection in recent years and the vast majority of species are in high demand by collectors. Whilst there is no evidence of illegal collection at the time of this submission, closely related species, including some from the immediate area, have been illegally removed from habitat with a dramatic increase in the number of species and volume of plants targeted since 2019. The threat of illegal collection is therefore regarded as very high for this particular succulent. Given its single location and small population size (less than 5,000 mature individuals) a complete decline of up to 100% of the population is likely within the next 10 years. Climate change is also impacting the population although there is uncertainty of the response given the expected resilience of this taxon. It therefore qualifies as Critically Endangered under criteria A3 and B1+2. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This succulent is endemic to the Northern Cape province of South Africa where it is only found in a single location with a restricted geographic range. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Vyftienmyl se Berge Succulent Shrubland |
Description | This succulent is endemic to the Richtersveld bioregion of the Succulent Karoo biome. It is restricted to sheltered quartz cliff faces, occupying cracks and fissures, where it regularly receives exposure to fog (probably the primary source of moisture).
This taxon 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 particular succulent is not currently threatened by illegal collection but it is likely that it will become a target in coming years as there has been a dramatic increase in the number of species and volume of plants of this genus targeted since 2019. Related species within the immediate area have experienced severe declines in population number due to illegal collection. The plants are severely range-restricted which renders them highly susceptible to a rapid decline in number through collection or other adverse events. The single location is well known for its succulent diversity and richness and has been regularly targeted by poachers in recent years. The threat of illegal collection in the future is therefore extremely high and as a result a population decline of 75-100% is suspected over three generations (90 years).
Anthropogenic climate change is a long-term threat to this succulent. Loss of vegetation cover has been observed across the geographic range occupied by this taxon 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 24% and 26% by 2080 for this succulent. However, as this taxon occurs in a very sheltered habitat it is expected to have a level of resilience to climate change and the expected population loss is reduced by 20% to 4%. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. |
Population |
It is uncommon and typically found in patches consisting of small numbers of individuals. There are no formal estimates of population size for this taxon but the number of mature individuals is probably less than 5,000. Due to an extended drought in the Richtersveld that started in 2016 and is still ongoing at the time of assessment, the population is suspected to be declining.
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Population trend | Unknown |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum obscurum N.E.Br. subsp. barbatum (L.Bolus) S.A.Hammer | VU D1+2 | 2015.1 | | Conophytum obscurum N.E.Br. subsp. barbatum (L.Bolus) S.A.Hammer | Data Deficient (Taxonomically Problematic) | 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 obscurum N.E.Br. subsp. barbatum (L.Bolus) S.A.Hammer. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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