Taxonomy
Scientific Name
Crassothonna clavifolia (Marloth) B.Nord.
Higher Classification
Dicotyledons
Family
ASTERACEAE
Synonyms
Othonna clavifolia Marloth
National Status
Status and Criteria
Endangered A2acd+4acd; B1ab(ii,iii,v)+2ab(ii,iii,v)
Assessment Date
2022/08/11
Assessor(s)
N.N. Mhlongo, D. Raimondo, P.C.V. Van Wyk & N.A. Helme
Justification
This species has a limited distribution range and has as an extent of occurrence (EOO) of 431 km² and an area of occupancy (AOO) of 32 km². It is known from 4 locations in the Northern Cape that continue to decline due to illegal collection, mining and habitat degradation due to livestock overgrazing. An estimated 50% of the population has been lost over the past 100 years, and a further 20% is suspected to be lost as a result of poaching and ongoing habitat loss over the next 50 years (generation length 50 years). It therefore qualifies as Endangered under criteria A and B. Since there is only one subpopulation known from Namibia and it is unknown how this species disperses, the regional assessment is not adjusted.
Distribution
Endemism
Not endemic to South Africa
Provincial distribution
Northern Cape
Range
This species is endemic to the Richtersveld area in the Northern Cape province and extends to Luderitz in southern Namibia.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Central Richtersveld Mountain Shrubland, Western Gariep Hills Desert, Western Gariep Lowland Desert, Noms Mountain Desert, Lower Gariep Alluvial Vegetation
Description
Plants occur on gravel-like and stony flats and slopes. Plants are remarkably resilient to the impacts of drought and no drought related mortality has been observed during the extended drought that has impacted its range from 2012 and is still ongoing at the time of assessment.
Threats
This species is threatened by illegal harvesting to supply the international succulent trade and the majority of plants observed on online markets show distinctive signs of being of wild origin. In addition, 40% of this species' habitat has been lost in South Africa due to shifting sands caused by the destabilisation of a dune system as a result of heavy livestock grazing between 2002 and 2014. Mining has resulted in a further 10% of the South African portion of its habitat being lost. Should the green hydrogen projects being proposed for the region be approved then this species will lose a substantial portion of its habitat, since the exact footprint of this proposed development is not yet known the overall future impact is difficult to determine.
Population

The population is in continuous decline as a result of illegal collection with 622 plants included in confiscations between March 2019 and December 2021, many more have been removed from the wild but were not intercepted by law enforcement efforts. For example tracking trade on the internet indicated that 2000 plants reached Hongkong and Hungary in 2015. In 2021 an estimated 5000 mature individuals got removed by poachers. The population is also declining as a result of habitat loss and degradation from mining and the impacts of livestock farming.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Crassothonna clavifolia (Marloth) B.Nord.Least Concern 2015.1
Othonna clavifolia MarlothLeast Concern Raimondo et al. (2009)
Bibliography

Nordenstam, B. 2012. Crassothonna B.Nord., a new African genus of succulent Compositae-Senecioneae. Compositae Newsletter 50:70-77.


Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.


Snijman, D.A. 2013. Plants of the Greater Cape Floristic Region 2: The extra Cape flora. Strelitzia 30. South African National Biodiversity Institute, Pretoria.


Citation
Mhlongo, N.N., Raimondo, D., Van Wyk, P.C.V. & Helme, N.A. 2022. Crassothonna clavifolia (Marloth) B.Nord. National Assessment: Red List of South African Plants version . Accessed on 2024/06/14

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Distribution map


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