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Scientific Name | Geissorhiza tricolor Goldblatt & J.C.Manning |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
National Status |
Status and Criteria | Endangered B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v) |
Assessment Date | 2023/06/20 |
Assessor(s) | N.A. Helme, L. von Staden & D. Raimondo |
Justification | This species has an extent of occurrence (EOO) and area of occupancy (AOO) of 12 km². It is known from two locations. This species continues to decline due to ongoing habitat loss to housing development. It is therefore listed as Endangered under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | It is endemic to the Western Cape province of South Africa, and is found in Riversdale. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Eastern Ruens Shale Renosterveld, Ruens Silcrete Renosterveld |
Description | It occurs in ferricrete soils in renosterveld-fynbos transition vegetation. |
Threats |
| This species has lost 85% of its habitat (calculated using landcover data in GIS) to crop cultivation and urban expansion. Most of this species' habitat is already transformed, mainly for crop cultivation, and remaining subpopulations are found on small fragments of natural vegetation. |
Population |
Two subpopulations are currently known, that occur less than 2 kilometres apart, one is protected within a nature reserve, the other is declining due to ongoing habitat loss to housing development. Although localized, it is estimated that each subpopulation consists of more than 50 plants (N.A. Helme pers. comm.). It is however, a recently discovered species, and there may be one or two more subpopulations in similar fragments around Riversdale.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Geissorhiza tricolor Goldblatt & J.C.Manning | EN B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v) | 2011.1 | |
Bibliography |
Goldblatt, P. and Manning, J.C. 2020. Iridaceae of southern Africa. Strelitzia 42. South African National Biodiversity Institute, Pretoria.
Goldblatt, P., Manning, J.C. and Nänni, I. 2009. New species of Geissorhiza (Iridaceae:Crocoideae) from the southern African winter rainfall zone, range extensions, taxonomic changes, and notes on pollen morphology. Bothalia 39(2):123-152.
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Citation |
| Helme, N.A., von Staden, L. & Raimondo, D. 2023. Geissorhiza tricolor Goldblatt & J.C.Manning. National Assessment: Red List of South African Plants version . Accessed on 2024/09/14 |
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