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Scientific Name | Conophytum rugosum S.A.Hammer |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
National Status |
Status and Criteria | Endangered A4d |
Assessment Date | 2023/10/26 |
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 dwarf succulent species is endemic to the Northern Cape and Western Cape provinces of South Africa where it has an extent of occurrence (EOO) of 3,618 km² and an area of occupancy (AOO) of 108 km². The population is in rapid decline due to illegal collection for the international trade in ornamental succulents as more than 24,000 plants have been removed from habitat since 2019. Illegal collection is likely to increase as there has been a dramatic increase in the number of species and volume of plants targeted since 2019. This species has a short generation length and is challenging to grow in cultivation. The continued threat of illegal collection is therefore regarded as extremely high for this particular species. The relatively large population size and scattered distribution across numerous populations across its geographic range is suspected to limit the decline to 75% of the population within the next three generations (45 years). It therefore qualifies as Endangered under criterion A4. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape, Western Cape |
Range | This species is endemic to the Western Cape and Northern Cape province of South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Namaqualand Klipkoppe Shrubland, Kamiesberg Mountains Shrubland, Southern Namaqualand Quartzite Klipkoppe Shrubland, Namaqualand Heuweltjieveld |
Description | This succulent species is found in the Namaqualand Hardeveld, Granite & Dolerite Renosterveld and Sandstone Fynbos bioregions of the Succulent Karoo and Fynbos biomes. The plants occupy, often en masse, shallow grit-filled pans on large expanses of granite and gneiss. They often favour damp areas with lichen and moss.
This species has a generation length of 15 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 |
| Plants have been subject to illegal collection of mature individuals for the international trade in ornamental succulents with more than 24,000 plants removed from habitat since 2019. This particular taxon has been highly sought after by collectors and is highly likely to remain so in future.
There is no decline in habitat quality for this species 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). Anthropogenic climate change is however a long-term threat to this succulent. 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 53% and 98% by 2080 for this taxon. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. However, this species possesses traits that are expected to provide some resilience, and given the uncertainty of this species' response to climate change and the fact that it has a generation length of only 15 years, climate predictions are not used to inform the overall assessment. |
Population |
It is known from numerous subpopulations where it may be locally abundant. There are no formal estimates of population size for this species but the number of mature individuals is likely to be between 100,000 and 150,000. The population is in decline due to illegal collection for the ornamental succulent plant trade. At least 24,000 plants have been removed from habitat between 2019 and the end of 2021 based on confiscation records, with many more having likely been removed but not intercepted by law enforcers.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum rugosum S.A.Hammer | Least Concern | Raimondo et al. (2009) | | Conophytum rugosum S.A.Hammer subsp. rugosum | Lower Risk - Least Concern | Victor (2002) | | Conophytum rugosum S.A.Hammer | Rare | Hilton-Taylor (1996) | |
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. 2023. Conophytum rugosum S.A.Hammer. National Assessment: Red List of South African Plants version . Accessed on 2024/12/07 |
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