Pteronia oppositifolia

Taxonomy
Scientific Name
Pteronia oppositifolia L.
Higher Classification
Dicotyledons
Family
ASTERACEAE
National Status
Status and Criteria
Data Deficient - Insufficient Information
Assessment Date
2016/01/28
Assessor(s)
L. von Staden, J.H. Vlok & A.R. Magee
Justification
A widespread, but apparently very rare and poorly known species. It is quite likely threatened by overgrazing and habitat loss to agriculture, but too little is known about its population size and trends, and therefore its risk of extinction cannot be assessed at present.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Touwsrivier to Mossel Bay.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Fynbos, Succulent Karoo
Description
Dry stony flats and slopes with clay soils.
Threats
Plants are heavily browsed by game and livestock, and may have disappeared in some parts of its range due to overgrazing (J.H. Vlok pers. comm. 2016). In the Overberg it is likely to have declined due to habitat loss to crop cultivation.
Population

Pteronia oppositifolia is a widespread, but very poorly known species. There are only four collections of it in SANBI herbaria, and three of these are more than 100 years old. Small, scattered subpopulations are known to occur in the Anysberg Nature Reserve near Ladismith in the Little Karoo (J.H. Vlok pers. comm. 2016), and it was recently observed in a small renosterveld fragment near Swellendam in the Overberg. The reason for the lack of records is not understood, but there are two possible explanations. Plants are highly palatable, and in many parts of the Little Karoo heavy overgrazing has reduced many shrubs to unrecognisable stumps, and such plants very rarely flower, which makes them easy to overlook and very difficult to identify (J.H. Vlok pers. comm. 2016). Secondly, Pteronia is in need of taxonomic revision, and Pteronia oppositifolia may be part of an unresolved species complex, and therefore possibly misidentified as other taxa (A.R. Magee pers. comm. 2016).


Population trend
Unknown
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Pteronia oppositifolia L.Threatened Raimondo et al. (2009)
Bibliography

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.


Harvey, W.H. 1894. Compositae. In: W.H. Harvey and O.W. Sonder (eds). Flora Capensis III (Rubiaceae to Campanulaceae):44-530. L. Reeve & Co., Ltd., Ashford.


Hutchinson, J. and Phillips, E.P. 1917. A revision of the genus Pteronia (Compositae). Annals of the South African Museum 9:277-329.


Manning, J.C. and Goldblatt, P. 2012. Plants of the Greater Cape Floristic Region 1: The Core Cape Flora. Strelitzia 29. South African National Biodiversity 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.


Vlok, J. and Schutte-Vlok, A.L. 2010. Plants of the Klein Karoo. Umdaus Press, Hatfield.


Citation
von Staden, L., Vlok, J.H. & Magee, A.R. 2016. Pteronia oppositifolia L. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2017/03/27

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Distribution map

© J.H. Vlok/A.L. Schutte-Vlok


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