|
Scientific Name | Ixia versicolor G.J.Lewis |
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 | 2015/06/30 |
Assessor(s) | P. Goldblatt, J.C. Manning, D. Raimondo & L. von Staden |
Justification | EOO <34 km², AOO <2km², two severely fragmented subpopulations remain after more than 90% habitat loss to urban expansion, and decline due to ongoing habitat loss and degradation continues. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | Stellenbosch to Gordon's Bay. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Swartland Shale Renosterveld, Lourensford Alluvium Fynbos |
Description | Seasonally wet clay flats. |
Threats |
| This species is endemic to Critically Endangered Lourensford Alluvium Fynbos, of which only 9% remains after extensive loss to urban expansion around Somerset West and Gordon's Bay. Remaining subpopulations of this species continue to be threatened by ongoing habitat loss and fragmentation due to urban and industrial development, competition from alien invasive plants, and inappropriate management of small fragments in terms of fire and mowing. |
Population |
This species is known from two remaining subpopulations, isolated as a result of habitat loss to urban expansion. The largest remaining subpopulation occurs at Gordon's Bay, and is partially protected in a small urban reserve. This species was frequently recorded on large open spaces on the flats surrounding this reserve in the 1980s, 1990s and early 2000s, but increasing development pressure has seen a steady reduction in the extent of alluvium fynbos in this area, and soon this species is likely to be confined to the reserve boundaries. Recent counts estimate the size of this subpopulation to be between 500 and 1000 mature individuals.
A second subpopulation survives in an urban park in a suburb of Somerset West, about 7 km from the Gordon's Bay subpopulation. The size of this subpopulation is not known, but is likely to be significantly smaller than the Gordon's Bay subpopulation, which occurs over an area of about 27 ha, while the park in Somerset West is only about 2 ha.
|
Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Ixia versicolor G.J.Lewis | CR A2ac; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) | Raimondo et al. (2009) | | Ixia versicolor G.J.Lewis | Vulnerable | Hilton-Taylor (1996) | | Ixia versicolor G.J.Lewis | Indeterminate | Hall et al. (1980) | |
Bibliography |
De Vos, M.P. 1999. Ixia. In: O.A. Leistner (ed). Flora of Southern Africa 7 Iridaceae Part 2: Ixioideae, Fascicle 1: Ixieae:3-87. National Botanical Institute, Pretoria.
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. 2016. Systematics of the southern African genus Ixia L. (Iridaceae): 5. Synopsis of section Ixia, including five new species. South African Journal of Botany 104:175-198.
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
Lewis, G.J. 1962. South African Iridaceae. The genus Ixia. Journal of South African Botany 28:45-195.
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.
|
Citation |
| Goldblatt, P., Manning, J.C., Raimondo, D. & von Staden, L. 2015. Ixia versicolor G.J.Lewis. National Assessment: Red List of South African Plants version . Accessed on 2024/10/08 |
Comment on this assessment
