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Scientific Name | Geissorhiza malmesburiensis R.C.Foster |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
National Status |
Status and Criteria | Critically Endangered B1ab(i,ii,iii,iv,v) |
Assessment Date | 2023/06/06 |
Assessor(s) | P. Goldblatt, N.A. Helme, R.C. Turner, L. von Staden & T. Patel |
Justification | This species has an extent of occurrence (EOO) of 93 km² and an area of occupancy (AOO) of 28 km². Four small, isolated, severely fragmented subpopulations remain after more than 80% of its habitat has been lost, predominantly to expanding crop cultivation. A surviving subpopulation of fewer than 500 mature individuals continue to decline due to ongoing habitat loss to urban expansion around Malmesbury, and competition from alien invasive plants and agricultural expansion at two other locations. It is therefore listed as Critically Endangered under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | It is endemic to Western Cape, South Africa, and is restricted to the immediate vicinity of Malmesbury. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Shale Renosterveld, Swartland Granite Renosterveld |
Description | It occurs in renosterveld, on granitic sands. |
Threats |
| This species has lost 83% of its habitat (calculated using landcover data in GIS) to wheat cultivation over the past 70 years. It is currently threatened by urban expansion around the town of Malmesbury. Agricultural activities and invasive alien plants are causing ongoing decline to two other remaining extant subpopulations. |
Population |
Four small, isolated subpopulations remain, three consisting of between 100 and 150 mature individuals, and the third has less than 10 mature individuals. The total population is suspected to be less than 500 individuals.
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Population trend | Decreasing |
Conservation |
| It is not currently conserved in any formally protected area. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Geissorhiza malmesburiensis R.C.Foster | CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); D | Raimondo et al. (2009) | | Geissorhiza malmesburiensis R.C.Foster | Endangered | Hilton-Taylor (1996) | |
Bibliography |
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 |
| Goldblatt, P., Helme, N.A., Turner, R.C., von Staden, L. & Patel, T. 2023. Geissorhiza malmesburiensis R.C.Foster. National Assessment: Red List of South African Plants version . Accessed on 2024/09/08 |
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