Kraaifontein Spiderhead

Taxonomy
Scientific Name
Serruria furcellata R.Br.
Higher Classification
Dicotyledons
Family
PROTEACEAE
Synonyms
Serruria diffusa R.Br.
Common Names
Kraaifontein Spiderhead (e)
National Status
Status and Criteria
Critically Endangered A2ac; B1ab(iii)+2ab(iii); C1+2a(i,ii); D
Assessment Date
2020/06/04
Assessor(s)
A.G. Rebelo, D. Raimondo, L. von Staden & D. Gibbs
Justification
Serruria furcellata is a long-lived species (generation length over 100 years) that is endemic to the northern parts of the Cape Flats area of the City of Cape Town, South Africa. The vast majority of this species habitat has been lost to urban development and remaining natural areas are severely degraded, only one mature individual from the original population remains extant. Declines over the past one generation (100 years) exceeds 99%. Reintroduction work is underway and it is hoped that newly introduced subpopulation will be viable and able to recruit independently, however long-lived resprouting species typically have extremely low recruitment success so the odds for this species are not favorable. It currently qualifies as Critically Endangered under criteria A,B,C, and D.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species is known from the northern Cape Flats area of the City of Cape Town occurring between Brackenfell, Bottelary and Kraaifontein in the Western Cape Province of South Africa.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Boland Granite Fynbos, Cape Flats Sand Fynbos
Description
It grows on sandy flats and occurs at low altitudes of 0-100 m.a.s.l. It is a long-lived species, and survives fires by resprouting from underground boles or rootstocks, the generation length is suspected to be over 100 years. Seeds are released after ripening, and dispersed by ants to their underground nests, where they are protected from predation by rodents and germinate following fire. It is pollinated by insects. No seedlings of this species have ever been observed, poor recruitment for long lived resprouters is a common phenomenon for Fynbos species.
Threats
A total of 86% of this species' habitat has been irreversibly modified for the urban and industrial development of the City of Cape Town, 38% of this loss has taken place since 1990. Remaining habitat has been badly degraded due to invasive alien plant invasions, brush-cutting, over-burning, invasive alien ants, and increased mole rat activity associated with disturbance. The only known remaining subpopulation occurs at a tiny site smaller than one hectare which is severely degraded.
Population

Herbarium records indicate that this species had a very small historic range occurring in an area of 6 by 8 kms. There are only three subpopulations that have been known since the 1970s, two have gone extinct. These include the subpopulation at Bellvue where 300 plants occurred in 1978, 15 in 1982 and none were seen after 1992 and the subpopulation at Koelenhof where no plants were found despite extensive searches between 1994-2000. It was last recorded in the 1970s. The only known remaining wild population is from North Pine (Scottsdene) where there were 150 plants in 6 ha in 1978 with another 150 in the surrounding 14 ha (Hall, 1982), but by 1982 there were only 120 plants due to housing developments. During 1992 and 2003 no plants could be found, but in 2004 two plants were found on a tiny corner of a site that had been turned into a commonage. In 2005, one of the plants was killed by mole rat activity. Reintroduction work has taken place and five plants were planted but only two survived, these have not yet produced viable recruits and are hence not yet counted as part of the wild population. Furthermore this last remaining individual occurs in a very small remnant, under one ha in size and is highly degraded, there is no long term viability for this subpopulation. Additional sites where this species has been reintroduced include Bracken Nature Reserve where there are now 30 well established plants. A further 150 plants were introduced in the winter of 2019 to Jack Muller Park and 30 have survived. The reintroduction work at Haasendal Private Nature Reserve has thus far been unsuccessful, all plants introduced here have died. As this species is a resprouter it is likely to have poor recruitment from seeds, and thus the chance of viable offspring being produced is very low. None of the reintroduced subpopulations have yet been burnt so none are yet considered part of the wild population. The total population thus now consists of the one individual surviving at North Pine.


Population trend
Decreasing
Conservation
This species is not conserved and its entire former habitat has been destroyed.
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Serruria furcellata R.Br.CR A2c; B1ab(i,ii,iii,iv,v)c(iv)+2ab(i,ii,iii,iv,v)c(iv); C1+2a(i,ii)b; DRaimondo et al. (2009)
Serruria furcellata R.Br.Endangered Hilton-Taylor (1996)
Serruria furcellata R.Br.Endangered Hall et al. (1980)
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.


Hall, A.V. 1982. Rare plants Gazette No 1. February 1982. Bolus Herbarium, University of Cape Town.


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.


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.


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., Raimondo, D., von Staden, L. & Gibbs, D. 2020. Serruria furcellata R.Br. National Assessment: Red List of South African Plants version . Accessed on 2024/10/06

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Distribution map

© C. Paterson-Jones

© I. Ebrahim


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