Tulbaghia siebertii

Taxonomy
Scientific Name
Tulbaghia siebertii (Vosa) Mich.Moller & G.I.Stafford
Higher Classification
Monocotyledons
Family
ALLIACEAE
Synonyms
Prototulbaghia siebertii Vosa
National Status
Status and Criteria
Endangered B1ab(ii,iii,v)+2ab(ii,iii,v)
Assessment Date
2013/07/25
Assessor(s)
S.J. Siebert & L. von Staden
Justification
A range-restricted (EOO 5 km²), localized habitat specialist (AOO <1 km²), occurring at two known locations and declining due to ongoing habitat loss and degradation as a result of overgrazing and road construction. The small population of fewer than 4000 mature individuals is also potentially threatened by mining. It is therefore assessed as Endangered under criterion B.
Distribution
Endemism
South African endemic
Provincial distribution
Limpopo
Range
This species is found in Sekhukhuneland, southern summit of the Leolo Mountains.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Sekhukhune Mountain Bushveld
Description
Plants grow in seeps between sheets of exposed norite bedrock above 1800 m.
Threats
One subpopulation was partially destroyed as a result of road construction (S.J. Siebert pers. obs.) and another site was noted to be under the impact of severe overgrazing (A.E. van Wyk specimen in PRU). This species is endemic to mineral rich norite substrate which is targeted for mining, and both sites are potentially threatened by habitat loss to mining.
Population

This species is currently known from two sites less than 2 km apart, where about 3000 plants have been counted (Siebert et al. 2005) at one site, and a further 1500 at the second (S.J. Siebert pers. comm.). About 20% of the larger subpopulation was destroyed as a result of road construction.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Prototulbaghia siebertii VosaEN B1ab(ii,iii,v)+2ab(ii,iii,v)2014.1
Bibliography

Craib, C. and Siebert, S.J. 2002. A new genus related to Tulbaghia from seepage areas on the summit of the Leolo Mountains in Sekhukhuneland, South Africa. Herbertia 57:85-90.


Siebert, S., Vosa, C., Van Wyk, A.E. and Muller, H. 2008. Prototulbaghia (Alliaceae), a new monotypic genus from Sekhukhuneland, South Africa. Herbertia 62:76-84.


Stafford, G.I., Wikkelso, M.J., Nancke, L., Jager, A.K., Moller, M. and Ronsted, N. 2016. The first phylogenetic hypothesis for the southern African endemic genus Tulbaghia (Amaryllidaceae, Allioideae) based on plastid and nuclear DNA sequences. Botanical Journal of the Linnean Society 181:156–170.


Vosa, C.G. 2007. Prototulbaghia, a new genus of the Alliaceae family from the Leolo Mountains in Sekhukhuneland, South Africa. Caryologia 60(3):273-278.


Vosa, C.G., Siebert, S.J. and Van Wyk, A.E. 2011. ALLIACEAE: Micromorphology and cytology of Prototulbaghia siebertii, with notes on its taxonomic significance. Bothalia 41(2):311-314.


Vosa, C.G., Van Wyk, A.E., Siebert, S.J. and Condy, G. 2011. Prototulbaghia siebertii. Flowering Plants of Africa 62:22-28.


Citation
Siebert, S.J. & von Staden, L. 2013. Tulbaghia siebertii (Vosa) Mich.Moller & G.I.Stafford. National Assessment: Red List of South African Plants version . Accessed on 2025/04/14

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Distribution map

© A.E. van Wyk


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