Taxonomy
Scientific Name
Aloe nubigena Groenew.
Higher Classification
Monocotyledons
Family
ASPHODELACEAE
National Status
Status and Criteria
Rare
Assessment Date
2020/01/13
Assessor(s)
M. Lötter, J.E. Burrows & L. von Staden
Justification
Aloe nubigena is a range-restricted, but locally common species. There are no severe threats to the population, and therefore it is not suspected to be in danger of extinction.
Distribution
Endemism
South African endemic
Provincial distribution
Mpumalanga
Range
This species is endemic to the edge of the Mpumalanga Drakensberg Escarpment between Mariepskop and Graskop.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Northern Escarpment Quartzite Sourveld
Description
It is localized to the upper parts of steep south- to east-facing cliffs above forested gorges at the edge of the escarpment.
Threats
Much of the surrounding grasslands within the distribution range of A. nubigena have been converted to forestry plantations (Craib 2005). The specific micro-habitat of this species is however unsuited to the establishment of plantations, and it is unlikely to have directly impacted the population. Escaped invasive pine seedlings are a potential threat to some subpopulations, as they are likely to outcompete native species if they are not cleared. According to Craib (2005), pine plantations as well as grazing cattle could degrade and disrupt the drainage of montane seeps above the escarpment cliffs, reducing moisture runoff. However, the main source of moisture to A. nubigena is probably precipitation from mist, and it is therefore unlikely to be affected by this type of habitat degradation. Plants in easily accessible sites at the cliff tops around popular tourist destinations are potentially threatened by illegal collecting, but no significant population decline due to collecting have yet been observed. Therefore, although there are several potential threats to this species, all are localized and likely to impact only a small proportion of the population, and are therefore unlikely to rapidly cause this species to become Critically Endangered or extinct within a short time.
Population

Aloe nubigena is a localized endemic, but is very common within suitable habitat within its range. It is known from at least 10 subpopulations, but there are likely to be many more on inaccessible cliffs. A very small proportion of the population (<10%) occurs in shallow pockets of soil among large sheet rocks at the top of cliffs. These plants have been impacted by habitat degradation and illegal succulent collecting in the past, but the majority of the population is not threatened and therefore assumed to be stable.


Population trend
Stable
Notes
A disjunct population of Aloe nubigena from the mountains south of Barberton was recently described as a separate species, Aloe condyae (Van Jaarsveld 2012).
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Aloe nubigena Groenew.Rare 2015.1
Aloe nubigena Groenew.VU D22014.1
Aloe nubigena Groenew.Least Concern 2013.1
Aloe nubigena Groenew.Least Concern Raimondo et al. (2009)
Aloe nubigena Groenew.VU D2Victor (2002)
Aloe nubigena Groenew.Not Threatened Hilton-Taylor (1996)
Bibliography

Craib, C. 2005. Grass Aloes in the South African Veld. Umdaus Press, Hatfield.


Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.


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.


Reynolds, G.W. 1969. The Aloes of South Africa. A.A. Balkema, Cape Town.


Smith, G.F., Steyn, E.M.A., Victor, J.E., Crouch, N.R., Golding, J.S. and Hilton-Taylor, C. 2000. Aloaceae: The conservation status of Aloe in South Africa: an updated synopsis. Bothalia 30(2):206-211.


Van Jaarsveld, E.J. 2012. Aloe condyae, a new cliff-dwelling aloe from Mpumalanga, Republic of South Africa. Bradleya 30:167-172.


Van Wyk, B.-E. and Smith, G. 1996. Guide to the aloes of South Africa. Briza Publications, 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
Lötter, M., Burrows, J.E. & von Staden, L. 2020. Aloe nubigena Groenew. National Assessment: Red List of South African Plants version . Accessed on 2025/04/11

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Distribution map

© D.R. McKenzie


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