Broad-leaf Featherbush

Taxonomy
Scientific Name
Aulax umbellata (Thunb.) R.Br.
Higher Classification
Dicotyledons
Family
PROTEACEAE
Synonyms
Aulax cneorifolia Salisb. ex Knight
Common Names
Broad-leaf Featherbush (e)
National Status
Status and Criteria
Least Concern
Assessment Date
2019/11/13
Assessor(s)
A.G. Rebelo, H. Mtshali & L. von Staden
Justification
Aulax umbellata is a widespread and common species. It is declining in parts of its range, but it is not yet in danger of extinction.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species is endemic to the Western Cape, where it occurs from Kogelberg to the Riviersonderend Mountains and Stilbaai.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Potberg Sandstone Fynbos, Overberg Sandstone Fynbos, Kogelberg Sandstone Fynbos, Canca Limestone Fynbos, De Hoop Limestone Fynbos, Agulhas Limestone Fynbos, Elim Ferricrete Fynbos, Albertinia Sand Fynbos, Agulhas Sand Fynbos, Hangklip Sand Fynbos
Description
It occurs in sandstone and limestone fynbos on mountains and flats. Mature individuals are killed by fires, and only seeds survive. Wind-dispersed seeds are stored in fire-resistant inflorescences, and released after fires. It is dioecious, with insect-pollinated male and female flowers occurring on separate plants.
Threats
About 20% of this species' habitat is irreversibly lost, mainly on the coastal lowlands, where ongoing coastal development is causing a continuing decline. The rate of habitat loss is however very low, with only 1% loss observed over 24 years, and therefore it is unlikely to exceed 30% within three generations. In the Riversonderend Mountains, on the Caledon Swartberg and on the Agulhas Plain, it is threatened by competition from alien invasive plants. In some areas, invasive species density is so great that native species are disappearing. Field observations also noted too frequent fire as a potential threat at some localities. As a serotinous reseeder, this species is vulnerable to local extinctions if fires kill individuals before they reach reproductive maturity.
Population

Within the core area of this species' range, from Betty's Bay to Bredasdorp and Potberg, it is abundant, occurring in extensive stands. It is comparatively rarer in the Riversonderend Mountains and the Canca area between Riversdale and Stilbaai. There are at least 60 extant subpopulations, with at least 13 estimated to consist of over 5000 mature individuals. Climate change models predicted a population reduction of more than 50% by 2025 (Bomhard et al. 2005), but such drastic declines have not yet materialized. A continuing decline is however inferred from observed ongoing habitat loss.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Aulax umbellata (Thunb.) R.Br.NT A2c+4cRaimondo et al. (2009)
Bibliography

Bomhard, B., Richardson, D.M., Donaldson, J.S., Hughes, G.O., Midgley, G.F., Raimondo, D.C., Rebelo, A.G., Rouget, M. and Thuiller, W. 2005. Potential impacts of future land use and climate change on the Red List status of the Proteaceae in the Cape Floristic Region, South Africa. Global Change Biology 11(9):1452-1468.


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.


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.


Rebelo, T. 2001. Sasol Proteas: A field guide to the proteas of southern Africa. (2nd ed.). Fernwood Press, Vlaeberg, Cape Town.


Citation
Rebelo, A.G., Mtshali, H. & von Staden, L. 2019. Aulax umbellata (Thunb.) R.Br. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/10/25

Comment on this assessment Comment on this assessment
Distribution map

© D. van der Colff

© D. Turner

© D. Turner

© I. Ebrahim

© I. Ebrahim


Search for images of Aulax umbellata on iNaturalist