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Scientific Name | Conophytum youngii Rodgerson |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
National Status |
Status and Criteria | Critically Endangered A2a+4ad; B1ab(v)+2ab(v); C1+2a(ii) |
Assessment Date | 2021/12/09 |
Assessor(s) | A.J. Young, D. Raimondo, P.G. Desmet, I. Ebrahim, D. Guo, A. Harrower, L. Jabar, L. Knoetze, C. Rodgerson & P.C.V. Van Wyk |
Justification | This cryptic succulent species 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 8 km2. This dwarf succulent has been increasingly targeted by illegal collection in recent years and is in high demand by collectors. More than 90% of the population was illegally collected for the international trade in ornamental succulents between 2019 and 2021. The continued threat of illegal collection of the few remaining plants (estimated to be fewer than 250) remains very high with the single location rendering the species highly susceptible to further rapid decline due to this activity. Climate change is also highly likely to impact the population although there is uncertainty of the response given the expected resilience of this taxon. It therefore qualifies as Critically Endangered under criteria A2+4, B1+2 and C1+2. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This species is endemic to the Northern Cape Province of South Africa where it is only found in a single location with a severely restricted geographic range. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Namaqualand Klipkoppe Shrubland |
Description | This dwarf succulent species is restricted to the Namaqualand Hardeveld bioregion of the Succulent Karoo biome. It is found on exposed areas of granite where it is found embedded in lichen and/or moss as well as in cracks and crevices.
This species has a generation length of 20 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 |
| There has been a substantial loss of mature individuals from the only known location due to illegal collection for the international trade in ornamental succulents since 2019. At least 90% of mature individuals have been removed from habitat in a very short period and the remaining plants are threatened. The species is especially susceptible to such impacts due to its limited geographic range and small population size. A complete loss of the population is expected within a single generation (20 years).
There is no decline in habitat quality for this taxon as inferred by changes in vegetation cover determined from changes in Enhanced Vegetation Index (EVI) between 1984 and 2018 using Landsat data (Venter et al. 2020). While it is not possible to model the response of this taxon 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. However, as this taxon typically occurs in a sheltered habitat and 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 52%. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. |
Population |
This recently discovered species is known from a single, large subpopulation consisting of several thousand individuals. It belongs to a small group of spring-flowering Conophytums (most species flower in autumn), which may explain why it has been overlooked until now, despite its habitat being well-explored. Its quite likely occurs on other similar granite domes in the area, but thus far, no more subpopulations have been found. Plants are extremely cryptic when not in flower, and may be easily overlooked. The population is currently stable, but is highly vulnerable due to its extremely localized distribution.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum youngii Rodgerson | CR B1ab(v)+2ab(v) | 2020.1 | | Conophytum youngii Rodgerson | VU D2 | 2017.1 | |
Bibliography |
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.
Rodgerson, C. 2012. The National Road and another new Conophytum. CactusWorld 30(4):239-244.
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Citation |
| Young, A.J., Raimondo, D., Desmet, P.G., Ebrahim, I., Guo, D., Harrower, A., Jabar, L., Knoetze, L., Rodgerson, C. & Van Wyk, P.C.V. 2021. Conophytum youngii Rodgerson. National Assessment: Red List of South African Plants version . Accessed on 2024/12/08 |
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