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Scientific Name | Conophytum antonii S.A.Hammer |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
National Status |
Status and Criteria | Critically Endangered A3d; B1ab(iii)+2ab(iii) |
Assessment Date | 2021/11/08 |
Assessor(s) | A.J. Young, P.G. Desmet, I. Ebrahim, D. Guo, 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 locality with an extent of occurrence (EOO) and area of occupancy (AOO) of 4 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 species given its single location and a complete decline of up to 100% of the population is possible within the next 10 years. The single location and inability to disperse also makes the species very susceptible to the deleterious effects of climate change. Loss of vegetation cover has been observed at this site via Landsat imagery between 1984 and 2018 and is used to infer that the habitat quality is already in decline. It therefore qualifies as Critically Endangered under criteria A3 and B1+2. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This dwarf succulent is endemic to the Northern Cape province of South Africa. It is restricted to a single isolated quartz-rich hill. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Namaqualand Klipkoppe Shrubland |
Description | This succulent is endemic to the Namaqualand Hardeveld bioregion of the Succulent Karoo biome. It is restricted to a single quartz-rich hill where it lives amongst large quartz rocks on the upper slopes. Plants are often found in the cracks and crevices of larger boulders which affords some protection from predation as well as shade. 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 Conophytum are sensitive to long periods of drought. Drought related mortality has been observed for other closely related taxa within the genus. |
Threats |
| This succulent is predicted to be threatened by harvesting for the specialist succulent trade. The highly restricted geographic range (AOO of 4 km2) coupled with the small population size at the only known locality makes the species very sensitive to such activity and rapid declines in mature individuals are possible and highly likely given the recent illegal harvesting to supply the new substantial demand from Asia for species within the genus.
There is an inferred decline in habitat quality at the only known locality for this species based on the loss of vegetation cover determined from changes in Enhanced Vegetation Index (EVI) between 1984 and 2018 using Landsat data (Venter et al. 2020).
Anthropogenic climate change is a long-term threat to this species. While it is not possible to model the response of this species to climate change due to its restricted distribution, the average loss to climate change for 15 more widely distributed Conophytum species occurring within the same region is used as an indication of likely impact to this species. 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 72% and 99% by 2080 for Conophytum taxa within the region. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. |
Population |
This species is locally abundant within suitable habitat (Hammer 2001). It is currently known from a single population, but occurs in a remote and poorly explored area, and it is possible that other subpopulations exist although none have been discovered in similar habitats nearby. Plants are extremely small and cryptic and could easily be overlooked, except when in flower. The population is estimated to have no more than 1,000 mature individuals. It is not yet declining but is predicted to decline in future due to illegal collection for the ornamental succulent plant trade and as a result of adverse climatic conditions.
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Population trend | Unknown |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum antonii S.A.Hammer | Critically Rare | 2017.1 | | Conophytum antonii S.A.Hammer | Rare | 2014.1 | |
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).
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Citation |
| Young, A.J., Desmet, P.G., Ebrahim, I., Guo, D., Jabar, L., Knoetze, L., Rodgerson, C., Van Wyk, P.C.V. & Mhlongo, N.N. 2021. Conophytum antonii S.A.Hammer. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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