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Scientific Name | Geissorhiza setacea (Thunb.) Ker Gawl. |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
National Status |
Status and Criteria | Endangered B2ab(i,ii,iii,iv,v) |
Assessment Date | 2023/06/17 |
Assessor(s) | D. Raimondo & T. Patel |
Justification | This species has an extent of occurrence (EOO) of 5244 km² and an area of occupancy (AOO) of 96 km². It occurs in small subpopulations (typically <250 plants) confined to isolated remnants of lowland renosterveld, after a loss of over 70% of its habitat to crop cultivation and urban expansion. It continues to decline, particularly in the Gordon's Bay, Strand and Durbanville areas. The population is severely fragmented. It is therefore listed as Endangered under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | It is restricted to the southwestern corner of Western Cape province, South Africa, extending from near Gouda in the north to the Cape Peninsula, the foot of the Hottentots Holland Mountains and possibly Caledon in the south. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Shale Renosterveld, Swartland Granite Renosterveld, Swartland Alluvium Renosterveld, Boland Granite Fynbos, Atlantis Sand Fynbos, Lourensford Alluvium Fynbos, Swartland Alluvium Fynbos |
Description | It occurs on wet sandy or loamy clay flats in renosterveld. |
Threats |
| This species has lost 72% of its habitat (calculated using landcover data in GIS) to urban expansion which is a severe past and ongoing threat especially at Gordon's Bay, Strand, Stellenbosch and the northern suburbs of Cape Town. Over 60% of habitat was lost to agriculture in the past 150 years. Competition from alien invasive plants is a moderate ongoing threat at Paardeberg and at Faure. |
Population |
The population has a decreasing trend and is known from 18 severely fragmented small subpopulations, typically having fewer than 250 mature individuals.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Geissorhiza setacea (Thunb.) Ker Gawl. | EN B1ab(i,ii,iii,iv,v) | Raimondo et al. (2009) | |
Bibliography |
Goldblatt, P. 1985. Systematics of the southern African genus Geissorhiza (Iridaceae-Ixioideae). Annals of the Missouri Botanical Garden 72(2):277-447.
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.
Goldblatt, P. and Manning, J.C. 2020. Iridaceae of southern Africa. Strelitzia 42. South African National Biodiversity 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 |
| Raimondo, D. & Patel, T. 2023. Geissorhiza setacea (Thunb.) Ker Gawl. National Assessment: Red List of South African Plants version . Accessed on 2024/09/08 |
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