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Scientific Name | Haworthia blackburniae W.F.Barker |
Higher Classification | Monocotyledons |
Family | ASPHODELACEAE |
National Status |
Status and Criteria | Near Threatened B1ab(iii,v)+2ab(iii,v) |
Assessment Date | 2022/10/06 |
Assessor(s) | J.H. Vlok, E.J. van Jaarsveld, D. Raimondo, N.A. Helme & L. von Staden |
Justification | A rare, range-restricted species, with an extent of occurrence (EOO) of 3729 km² and an area of occupancy of 68 km², occurs at between 10 and 15 locations. The population is declining predominantly due to the collection of mature individuals from the wild for the succulent trade. Therefore, it qualifies as Near Threatened under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This species is endemic to the Western Cape Province, where it occurs from Swartberg and the Little Karoo mountains. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Montagu Shale Renosterveld, Kango Limestone Renosterveld, Kango Conglomerate Fynbos, Central Inland Shale Band Vegetation, Western Gwarrieveld, Oudshoorn Karroid Thicket, Mons Ruber Fynbos Thicket, Gamka Valley Thicket |
Description | Plants can be found on steep, rocky slopes with a southern aspect in transitional karroid veld. |
Threats |
| This species is slow-growing and difficult to cultivate (Bayer 1982). Due to its rarity, it is popular in succulent collections, and subpopulations near roadsides have been cleared out by succulent collectors. More than 50% of the subpopulation near De Rust was removed by succulent traders in 1998 (J.H. Vlok pers. obs.). Along the foothills of the Swartberg Mountains, it is threatened by competition from alien invasive grasses and habitat loss to road construction. Plants occur in isolated rocky outcrops between cultivated fields, where it has been spared from habitat destruction due to its particular habitat being unsuitable to ploughing. |
Population |
This species is quite rare, occurring in small subpopulations, but is also easily overlooked.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Haworthia blackburniae W.F.Barker var. blackburniae | Least Concern | Raimondo et al. (2009) | | Haworthia blackburniae W.F.Barker var. derustensis M.B.Bayer | EN A2ad | Raimondo et al. (2009) | | Haworthia blackburniae W.F.Barker var. graminifolia (G.G.Sm.) M.B.Bayer | CR B1ab(iii,v) | Raimondo et al. (2009) | | Haworthia graminifolia G.G.Sm. | Rare | Hilton-Taylor (1996) | | Haworthia blackburniae W.F.Barker var. blackburniae | Rare | Hilton-Taylor (1996) | | Haworthia blackburniae W.F.Barker | Rare | Hall et al. (1980) | |
Bibliography |
Bayer, M.B. 1982. The new Haworthia handbook. National Botanical Gardens of South Africa.
Bayer, M.B. 1999. Haworthia Revisited: A revision of the genus. Umdaus Press, Hatfield.
Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
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.
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Citation |
| Vlok, J.H., van Jaarsveld, E.J., Raimondo, D., Helme, N.A. & von Staden, L. 2022. Haworthia blackburniae W.F.Barker. National Assessment: Red List of South African Plants version . Accessed on 2025/04/13 |
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