Holothrix micrantha

Taxonomy
Scientific Name
Holothrix micrantha Schltr.
Higher Classification
Monocotyledons
Family
ORCHIDACEAE
National Status
Status and Criteria
Critically Endangered (Possibly Extinct)
Assessment Date
2016/10/04
Assessor(s)
L. Mills & L. von Staden
Justification
A rare, range-restricted species last recorded in 1925. Several searches within its habitat have thus far failed to relocate this species in the wild. It is possibly extinct, but also cryptic and easily overlooked, and a small chance remain that it may still be relocated.
Distribution
Endemism
South African endemic
Provincial distribution
Gauteng
Range
Gauteng, Johannesburg to Heidelberg.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Gold Reef Mountain Bushveld, Egoli Granite Grassland
Description
Grassy cliffs, 1500-1800 m.
Threats
Urban expansion has caused the loss of subpopulations in the south of Johannesburg. Some intact habitat remains around Heidelberg, but there is ongoing loss and degradation due to development, inappropriate fire management and spreading, unmanaged alien invasive plants. Good condition, intact habitat remains in Suikerbosrand Nature Reserve, but the species' presence in the reserve has not been confirmed.
Population

This species is known from a few records from southern Johannesburg and the Heidelberg area. It was last collected in 1925. There were unconfirmed sightings of this species in the Suikerbosrand Nature Reserve some years ago, but many repeated searches by orchid specialists and Gauteng Conservation Department staff have thus far failed to relocate this species. The current population status and trend is not known, and it may be extinct.


Population trend
Unknown
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Holothrix micrantha Schltr.EN B1ab(iii)Raimondo et al. (2009)
Holothrix micrantha Schltr.EN A3c; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)Pfab and Victor (2002)
Holothrix micrantha Schltr.EN B1B2abcdeVictor (2002)
Holothrix micrantha Schltr.Insufficiently Known Hilton-Taylor (1996)
Holothrix micrantha Schltr.Uncertain Hall et al. (1980)
Bibliography

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.


Immelman, K.L. 1996. FSA contributions 6: Orchidaceae: Holothrix. Bothalia 26(2):125-140.


Johnson, S. and Bytebier, B. 2015. Orchids of South Africa: A field guide. Struik Nature, Cape Town.


Linder, H.P. and Kurzweil, H. 1999. Orchids of southern Africa. A.A. Balkema, Rotterdam.


Pfab, M.F. and Victor, J.E. 2002. Threatened plants of Gauteng, South Africa. South African Journal of Botany 68:370-375.


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.


Retief, E. and Herman, P.P.J. 1997. Plants of the northern provinces of South Africa: keys and diagnostic characters. Strelitzia 6. National Botanical Institute, Pretoria.


Victor, J.E. 2002. South Africa. In: J.S. Golding (ed), Southern African plant Red Data Lists. Southern African Botanical Diversity Network Report 14 (pp. 93-120), SABONET, Pretoria.


Citation
Mills, L. & von Staden, L. 2016. Holothrix micrantha Schltr. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2017/10/22

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