Taxonomy
Scientific Name
Senecio exuberans R.A.Dyer
Higher Classification
Dicotyledons
Family
ASTERACEAE
National Status
Status and Criteria
Endangered B1ab(ii,iii,iv)
Assessment Date
2006/07/27
Assessor(s)
L. von Staden, C.R. Scott-Shaw, P. Wragg & J.E. Victor
Justification
Known from five or fewer locations, from a very small area (EOO < 200 km²). It is undergoing a continuing decline as a result of urban expansion, industrial development, alien plant invasion and a deleterious fire regime. It has also lost habitat to crop cultivation and afforestation.
Distribution
Endemism
South African endemic
Provincial distribution
KwaZulu-Natal
Range
Formerly around Pietermaritzburg, now restricted to Drummond.
Habitat and Ecology
Major system
Terrestrial
Major habitats
KwaZulu-Natal Sandstone Sourveld, Moist Coast Hinterland Grassland, Dry Coast Hinterland Grassland
Description
Sandstone grasslands, 800-1000 m.
Threats
This tall, striking Senecio was once described as "one of the most characteristic features of the Midlands grasslands" around Pietermaritzburg and Drummond (Dyer 1943). However, it was only known from a handful of specimens, all collected prior to 1945 (Dyer 1943; Hilliard 1977; Scott-Shaw 1999), as most of these grasslands have since disappeared under agriculture, forestry and urban expansion of Pietermaritzburg. Between 1995 and 2006, four populations were rediscovered on small fragments of primary grasslands in the same area as the type locality at Drummond, between Pietermaritzburg and Pinetown (Wragg in prep., specimen in PRE). This species was severely threatened in the past by agriculture and forestry plantations. Agriculture (mainly sugarcane) transformed most of the sandstone plateaus around Pietermaritzburg in the past. The nutrient poor sandstone soils are, however, not as suitable to agriculture and many of the agricultural fields were abandoned around the 1970s (Wragg in prep.). Grasslands returned to these areas. However, they are very low diversity secondary grasslands, and herbaceous and other dicots are usually not to be found in them. Much of the grasslands were converted to pine plantations, especially north of Pietermaritzburg, where at least two known locations have been lost. Recent urban expansion, especially towards Hilton, is causing ongoing transformation of remaining grasslands (I. Johnson pers. comm.) Poorly managed grassland fragments are being encroached on by woody alien invasive species, and are either burnt too frequently (annually) or not at all. The Summerveld population is highly threatened by peri-urban/smallholding development - it is spread over several five acre plots, most of which contain a house and some of which are also used for grazing horses. One of the plots contains a conservation servitude over the portion containing the plants, but the owner nonetheless mows it every summer, preventing the plants from flowering. Some of the other plots presently have sympathetic landowners who manage the grassland properly (simply annual to biennial burning), but this could change easily if these properties are sold. Several parts of the population have been destroyed by people building houses. A lack of fire is also a foreseen threat, as the landscape is becoming fragmented and the wild fires, which presently burn into most of the grassland each year, become controlled by people to prevent the spread of fire to their homes. There is less certainty about Monteseel, but it appears to face similar threats of peri-urban development. Many remnant grassland patches were marked for sale. At Cato Ridge, the population is on one of the largest remaining undeveloped areas of flat land in the Durban-Pietermaritzburg corridor (the biggest development corridor in KwaZulu-Natal). This area has been earmarked as an industrial development node by the IDP, and serious proposals have been noted, ranging from a container storage area to be linked to Durban harbour by train (they are running out of container storage at the harbour) to an airport. David Styles was approached a few weeks back to do an assessment there for a tentative development proposal. Therefore, even though the immediate threats are minimal (the population is on land adjoining an airfield for small aircraft, and the only impact is annual burning and cattle grazing, which is doubted to be a serious problem), the long-term threats imposed by its strategic location appear to be overwhelming (P. Wragg pers. comm. 2007).
Population

The subpopulation at Summerveld is quite extensive and spread over several different smallholdings. As the main threat here is subdivision and development of these smallholdings, each property should be considered a separate location. The same situation also applies at Monteseel. The Cato Ridge airfield subpopulation is threatened by a large scale industrial development (an environmental impact assessment is underway) and this should be considered one location. The other two potential sites (Hammarsdale and Worlds View) are considered single locations until more information becomes available.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Senecio exuberans R.A.DyerEN B1ab(ii,iii,iv)Raimondo et al. (2009)
Senecio exuberans R.A.DyerEN Scott-Shaw (1999)
Senecio exuberans R.A.DyerIndeterminate Hilton-Taylor (1996)
Bibliography

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.


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


Citation
von Staden, L., Scott-Shaw, C.R., Wragg, P. & Victor, J.E. 2006. Senecio exuberans R.A.Dyer. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2023/02/08

Comment on this assessment Comment on this assessment
Distribution map

© L. Ground

© P. Wragg

© P. Wragg

© A. Young

© A. Young

© A. Young

© A. Young

© A. Young


Search for images of Senecio exuberans on iNaturalist