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Scientific Name | Conophytum herreanthus S.A.Hammer subsp. rex S.A.Hammer |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
National Status |
Status and Criteria | Endangered A3d |
Assessment Date | 2021/11/25 |
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 with an extent of occurrence (EOO) of 481 km² and area of occupancy (AOO) of 44 km². 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 taxon. A decline of 75% of the population is likely within the next three generations (90 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 Endangered under criterion A3. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This succulent is endemic to the Richtersveld in the Northern Cape province of South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Kosiesberg Succulent Shrubland |
Description | This dwarf succulent is endemic to the Richtersveld bioregion of the Succulent Karoo biome. The plants are typically found in the cracks and crevices of quartzite outcrops, in partial-shade or full sun. 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 likely 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. Anthropogenic climate change is a long-term threat to this taxon. Loss of vegetation cover has been observed across the geographic range occupied by this succulent 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 35% and 91% by 2080. However, as this taxon possesses certain traits likely to afford resilience to xerophytic conditions it is expected to have a level of resilience to climate change and the expected population loss is reduced by 20% to 15%. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. |
Population |
The numerous subpopulations of this succulent each consist of up to several hundred plants. The total population is likely to be between 5,000 and 15,000 mature individuals. The current population trend is unknown, however in response 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. The population is suspected to decline by 75% over the next three generations (90 years) as a result of illegal collection for the succulent ornamental trade.
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Population trend | Unknown |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum herreanthus S.A.Hammer subsp. rex S.A.Hammer | Rare | 2015.1 | | Conophytum herreanthus S.A.Hammer subsp. rex S.A.Hammer | 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 herreanthus S.A.Hammer subsp. rex S.A.Hammer. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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