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Scientific Name | Geissorhiza purpurascens Goldblatt |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
National Status |
Status and Criteria | Endangered B1ab(ii,iii,v)+2ab(ii,iii,v); C2a(i) |
Assessment Date | 2021/10/22 |
Assessor(s) | D. Raimondo, P. Goldblatt, R.C. Turner & T. Patel |
Justification | This species has an extent of occurrence (EOO) of 1474 km² and an area of occupancy (AOO) of 80 km². It is known from fourteen small, severely fragmented subpopulations that are under severe threat from crop cultivation, alien invasive wattle encroachment and urban development. The total population is suspected to be under 100 plants, with subpopulations typically small (<20 plants), and only three subpopulations with between 50 and 100 plants are known. Its seasonally wet lowland habitat is now very rare as a result of extensive transformation to crop cultivation and degradation due to invasive alien plants. It is therefore listed as Endangered under criteria B and C. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | It is rare and local in southwestern Western Cape province, South Africa, occurring between Paarl Mountain and the coast near Mamre and Darling but with an isolated subpopulation on the south slopes of the Piketberg. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Granite Renosterveld, Swartland Silcrete Renosterveld, Atlantis Sand Fynbos, Swartland Alluvium Fynbos |
Description | It grows in deep quartzitic sands, often in seasonally wet sites. |
Threats |
| This species has lost 60% of its habitat (calculated using landcover data in GIS), mainly due to agricultural expansion, and only small fragments remain. Known subpopulations all occur on isolated remnants of natural vegetation where they are threatened by ongoing habitat loss and degradation, overgrazing, urban expansion and competition from alien invasive plants. |
Population |
Fourteen small, isolated remaining subpopulations are currently known, three subpopulations have between 50 and 100 mature individuals. All other subpopulations monitored have less than 20 individuals. Decline is ongoing.
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Population trend | Decreasing |
Conservation |
| It has not been recorded from any formally protected areas. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Geissorhiza purpurascens Goldblatt | CR B2ab(iii,v); C2a(i) | 2012.1 | | Geissorhiza purpurascens Goldblatt | CR B2ab(iii,v); C2a(i) | Raimondo et al. (2009) | | Geissorhiza purpurascens Goldblatt | Vulnerable | Hilton-Taylor (1996) | |
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.
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 |
| Raimondo, D., Goldblatt, P., Turner, R.C. & Patel, T. 2021. Geissorhiza purpurascens Goldblatt. National Assessment: Red List of South African Plants version . Accessed on 2024/09/08 |
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