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Scientific Name | Watsonia humilis Mill. |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
Synonyms | Watsonia roseoalba Ker Gawl. |
Common Names | Rooipypie (a), Waspypie (a) |
National Status |
Status and Criteria | Critically Endangered B1ab(iii,v)+2ab(iii,v) |
Assessment Date | 2013/01/28 |
Assessor(s) | P. Goldblatt, J.C. Manning, D. Raimondo & L. von Staden |
Justification | A formerly widespread (historical EOO 3954 km²) and common species, which has declined to two, isolated, severely fragmented subpopulations (current EOO 93 km², AOO <1 km²), due to habitat loss to urban expansion, infrastructure development and agricultural expansion. It continues to decline due to ongoing habitat degradation and competition from alien invasive plants. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | Formerly occurred in the Breede River Valley between Tulbagh and Worcester, and the lowlands between Malmesbury, Franschhoek and Gordon's Bay. Two subpopulations remain: one at Gordon's Bay and a second, more than 80 km away, in the Breede River Valley near Wolseley. This species is absent from the Cape Peninsula. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Shale Renosterveld, Breede Shale Renosterveld, Swartland Alluvium Renosterveld, Breede Shale Fynbos, Boland Granite Fynbos, Cape Flats Sand Fynbos, Atlantis Sand Fynbos, Lourensford Alluvium Fynbos, Swartland Alluvium Fynbos, Breede Alluvium Fynbos |
Description | Seasonally wet clay and loamy alluvial flats. |
Threats |
| Habitat loss to agriculture, urban expansion and infrastructure development has caused at least 90% reduction in the range of this species. Remaining subpopulations are threatened by ongoing habitat degradation due to too frequent fire, dumping, pollution and urban expansion (Gordon's Bay), and competition from alien invasive plants (Breede River Valley). |
Population |
More than 90% of this species' locations known through historical records have been lost due to habitat destruction, and its EOO has been reduced by 98%. One small subpopulation of fewer than 50 plants remain in a small urban reserve at Gordon's Bay, and a second was recently (2012) rediscovered in the Breede River Valley near Worcester, separated by more than 80 km. More surveys are needed to determine the size of the second subpopulation, which is also confined to small remnants of natural vegetation.
The only known remaining subpopulation of this species consists of fewer than 50 mature individuals and continues to decline.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Watsonia humilis Mill. | CR B1ab(iii,v); C2a(i,ii); D | Raimondo et al. (2009) | | Watsonia humilis Mill. | Endangered | Hilton-Taylor (1996) | | Watsonia roseoalba Ker Gawl. | Indeterminate | Hall et al. (1980) | |
Bibliography |
Goldblatt, P. 1989. The genus Watsonia. A systematic monograph. Annals of Kirstenbosch Botanic Gardens 19:1-148. National Botanic Gardens, Cape Town.
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 |
| Goldblatt, P., Manning, J.C., Raimondo, D. & von Staden, L. 2013. Watsonia humilis Mill. National Assessment: Red List of South African Plants version . Accessed on 2025/05/21 |
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