Taxonomy
Scientific Name
Barleria argillicola Oberm.
Higher Classification
Dicotyledons
Family
ACANTHACEAE
National Status
Status and Criteria
Critically Endangered A3ce; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)
Assessment Date
2007/06/12
Assessor(s)
T. Makholela, K. Balkwill, F.H. van der Bank & L. von Staden
Justification
EOO 34.5 km², known from seven small, severely fragmented subpopulations, scattered over three farms. All known subpopulations are threatened by illegal informal settlements and land claims and there is currently continuing decline due to livestock overgrazing in at least one subpopulation and expected future declines in all others. We project that the total population is likely to decline by 80% over the next 60 years.
Distribution
Endemism
South African endemic
Provincial distribution
KwaZulu-Natal
Range
Between Weenen and Estcourt.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Thukela Thornveld, KwaZulu-Natal Highland Thornveld
Description
Savanna, in eroded doleritic soils or among dolerite boulders, 900-1200 m.
Threats
Threatened by ongoing habitat loss to expanding informal settlements and changes in land management due to land claims.
Population

According to Makholela et al. (unpubl.) there is one large subpopulation (1547 mature individuals) on the farm Rensburgspruit 872, two large subpopulations (1126 and 155 individuals) and three smaller ones (39, 110 and 131 mature individuals) along a road verge on the farm Van der Merwe's Kraal 972, and 651 mature individuals in the Weenen Nature Reserve. The population in the Weenen Nature Reserve was quite healthy at the time of the study (Makholela et al. unpubl.), and the only population that did not occur on eroded soils (T. Makholela pers. comm.) However, since then, an illegal informal settlement was established in the Weenen Nature Reserve, and this population is now severely threatened by the expansion of the settlement and increased grazing pressure that may lead to soil erosion (D. Styles pers. comm. 2007). Van der Merwe's Kraal and Rensburgspruit was privately owned and lightly grazed and there were plans to convert the farm into a nature reserve as another rare endemic, Barleria greenii, also occurs there. However, these farms were granted to a local community in a land claim (D. Styles pers. comm. 2007) and will certainly result in a change in the fire regime and grazing pressure (C.R. Scott-Shaw pers. comm.) One of the smaller populations along the roadside on Van der Merwe's Kraal was destroyed when the road was widened recently (T. Makholela pers. comm. 2007).


Population trend
Decreasing
Conservation
Weenen Nature Reserve.
Notes
This species appears to grow on severely eroded soils, however, whether or not it prefers eroded soils is not certain. The largest and healthiest populations occur on flat areas in the Weenen Nature Reserve and the farm Rensburgspruit that are not severely eroded, while smaller populations are found on eroded banks along roadsides on Van der Merwe's Kraal. It may be that the highly specific clay soils that this species is restricted to is more prone to erosion than surrounding soil types, and that populations on eroded areas are small remnants of former more extensive populations (T. Makholela pers. comm. 2007).
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Barleria argillicola Oberm.CR A3ce; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)Raimondo et al. (2009)
Barleria argillicola Oberm.Data Deficient Scott-Shaw (1999)
Barleria argillicola Oberm.Vulnerable Hilton-Taylor (1996)
Barleria argillicola Oberm.Rare Hall et al. (1980)
Bibliography

Balkwill, K. and Batten, A. 1999. Barleria greenii. Flowering Plants of Africa 56:106-109.


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.


Makhoela, T., Balkwill, K. and van der Bank, H.F. Unpublished. Allozyme diversity, reproductive biology and conservation in a rare and restricted clonal endemic, Barleria argillicola (Acanthaceae).


Makhoela, T., van der Bank, H. and Balkwill, K. 2003. A preliminary study of allozyme variation in three rare and restricted endemic Barleria greenii (Acanthaceae) populations. Biochemical Systematics and Ecology 31:141-154.


Makhoela, T.M., van der Bank, F.H. and Balkwill, K. 2004. Allozyme variation in Barleria saxatilis (Acanthaceae) is lower than in two congeneric endemics. South African Journal of Botany 70(4):515-520.


Mucina, L. and Rutherford, M.C. (eds). 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.


Obermeyer, A.A. 1933. Revision of the South African species of Barleria. Annals of the Transvaal Museum 15(2):123-180.


Obermeyer, A.A. 1961. Notes and new records of African plants: Barleria argillicola. Bothalia 7:444-445.


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.


Scott-Shaw, C.R. 1991. A taxonomic revision of the Acalypha peduncularis E.Mey ex Meisn. (Euphorbiaceae) complex in southern Africa. Unpublished M.Sc., University of Natal, Pietermaritzburg.


Scott-Shaw, C.R. 1999. Rare and threatened plants of KwaZulu-Natal and neighbouring regions. KwaZulu-Natal Nature Conservation Service, Pietermaritzburg.


Citation
Makholela, T., Balkwill, K., van der Bank, F.H. & von Staden, L. 2007. Barleria argillicola Oberm. National Assessment: Red List of South African Plants version . Accessed on 2025/04/19

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Distribution map

© H. Mtshali

© H. Mtshali


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