Steirodiscus tagetes…still here nearly 55 years later after claims of local extinction! This vulnerable plant has proven to be a tenacious survivor in its dwindling habitat. South Africa has over 20 000 plant species, 60% of which, occur nowhere else in the world. With the highest species diversity, it is unfortunately matched by the highest plant extinction rate; 37 species declared extinct, another 64 believed to be extinct.
According to FynbosLife, Cape Town has ten of South Africa’s 21 Critically Endangered national vegetation types, three of which are endemic to the city. The Cape Flats alone supports more than 1460 different plant species, of which 203 are threatened with extinction and five are globally extinct in the wild.
Habitat loss on the Cape Flats has caused this formerly widespread species to decline. SANBI’s Red List of South African Plants assessment (2016), revealed that this endemic flower only remains at six to eight locations along the West Coast, which continue to decline, and is currently listed as locally extinct on the Cape Flats. It is still thought to persist on the False Bay coast near Macassar, despite it last being recorded in this area in 1995.
Five herbarium specimen records exist from the Compton, University of the Western Cape (UWC) and Stellenbosch University’s herbariums dating from 1942 to 1978.
Through the concerted efforts of organisations like CREW (Custodians of Rare and Endangered Wild Flora) and plant enthusiasts posting to the platform i-Naturalist, Steirodiscus tagetes has been recorded at three locations on the Cape Flats, Diep River Corridor, Zandvlei Estuary Nature Reserve and Steenberg between 2018 and 2020.
Major habitats of Steirodiscus tagetes include the endangered Cape Flats Dune Strandveld and the critically endangered Cape Flats Sand Fynbos, both occuring at UWC’s, Cape Flats Nature Reserve. This 34ha private nature reserve is one of the locations for Steirodiscus tagetes, but has not as yet officially been recorded as a location. A 1982 Veld & Flora article, mentions how Steirodiscus tagates was one of the dominant species at UWC, predominating the open spaces below our dunes. It is still here since its first record in 1967.
With the vegetation on the Cape Flats being so threatened and fragmented, the importance of protected areas on the Cape Flats becomes clear. Steirodiscus tagetes has only been recorded at one other nature reserve, the Zandvlei Estuary, the other being an open space in Steenberg. UWC’s Cape Flats Nature Reserve is the oldest declared nature reserve on the Cape Flats, proclaimed in 1977. Conceptualised by UWC academics in the 1960s, it took 17 years for this idea to be actualized, but even then, they knew the importance of what needed protecting.
by Laurenda van Breda (Environmental Education & Research Officer, UWC Nature Reserve Unit, University of the Western Cape)