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Scientific Name | Geissorhiza helmei Goldblatt & J.C.Manning |
Higher Classification | Monocotyledons |
Family | IRIDACEAE |
National Status |
Status and Criteria | Critically Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) |
Assessment Date | 2023/05/29 |
Assessor(s) | N.A. Helme & D. Raimondo |
Justification | This is a recently discovered species known from one location. It has an extent of occurrence (EOO) and an area of occupancy (AOO) of 4 km². It has lost the majority of its habitat to wheat cultivation, and this loss is continuing with a shift in farming practices from wheat to rooibos tea. It is therefore listed as Critically Endangered under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | A narrow endemic of the lower northern slopes of the southern arm of the Piketberg Mountains in Western Cape province of South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Shale Renosterveld |
Description | It occurs in rocky ground in light sandy loam overlaying clay, and flowers only after fire. |
Threats |
| This species is under threat from habitat loss to crop cultivation, the majority of its habitat has been lost in the past to wheat cultivation. There is ongoing habitat conversion for the growing of rooibos tea. |
Population |
It is highly restricted, known from only one subpopulation where it is locally common. This subpopulation is decreasing as a result of slow but ongoing loss to crop cultivation.
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Population trend | Decreasing |
Notes |
| Flowering is fire dependent, with plants flowering only in the first year after fire. This species is therefore likely to be overlooked in mature vegetation. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Geissorhiza sp. nov. (Helme 4200 NBG) | CR B1ab(ii,iii,iv,v) | Raimondo et al. (2009) | |
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.
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 |
| Helme, N.A. & Raimondo, D. 2023. Geissorhiza helmei Goldblatt & J.C.Manning. National Assessment: Red List of South African Plants version . Accessed on 2024/09/14 |
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