|
Scientific Name | Serruria aemula Salisb. ex Knight |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Synonyms | Serruria ciliata R.Br. (in part), Serruria ciliata R.Br. var. ciliata, Serruria ciliata R.Br. var. congesta (R.Br.) Hutch. |
Common Names | Strawberry Spiderhead (e) |
National Status |
Status and Criteria | Critically Endangered B1b(iii,v)c(iv) |
Assessment Date | 2020/04/15 |
Assessor(s) | A.G. Rebelo, D. Raimondo, L. von Staden & J. van der Merwe |
Justification | Serruria aemula is a restricted endemic species which was recorded to be the most common protea on the Cape Flats at the turn of the century, extending from Salt River to Kraaifontein. Historically this species had an extent of occurrence (EOO) of 817 km². A total of 75% of its habitat has been irreversibly modified to urban and industrial expansion, 18% of this loss has taken place since 1990. This species is now restricted to an EOO of 76 km², and an area of occupancy (AOO) of 36 km². Remaining habitat is severely infested with alien plants and subject to multiple pressures associated with the urban environment. The largest remaining portion of the population occurs along the Platterkloof powerline servitude where it is highly threatened by the lack of burning. This is a reseeding species dependent on fire for recruitment, as 80% of individuals occur at this one location, the incorrect fire management at this site will lead to extreme fluctuations in population size. With ongoing severe degradation of this species habitat, there is continuing decline in the number of mature individuals in the population. This species therefore qualifies as Critically Endangered under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | An endemic species to the Western Cape Province of South Africa, occurring only on the Cape Flats area of the Cape Peninsula. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Cape Flats Sand Fynbos |
Description | It is confined to the Cape Flats Sand Fynbos occurring at altitudes of between 0-70 m.a.s.l. Mature individuals are killed by fires, and only seeds survive. Seeds are released after ripening, and dispersed by ants to their underground nests, where they are protected from predation and fire. It is pollinated by insects. |
Threats |
| Urban development for the City of Cape Town, both houses and industrial, has resulted in 75% of this species' habitat being irreversibly modified. Remaining remnants of suitable habitat are under significant ongoing pressure from invasive alien plants and invasive ants, inappropriate urban fire management, mowing (road verges and as a fire alternative under power lines), infrastructure (road, pipe and services maintenance), pollution (sewage spills), vagrants over nighting and informal houses for squatters being erected on state land. The site where 80% of the remaining population occurs, Platterfkloof Natural Heritage site, is experiencing ongoing decline in habitat quality and the number of mature individuals as the landowners, South Africa's Power company Eskom, are not prepared to burn the site in fear of damaging key powerlines that provide electricity to the city. |
Population |
Based on herbarium records, this species appears to have been widespread and common on the Cape Flats historically. The population has however experienced severe declines and now remains in only three subpopulations. The largest subpopulation occurs at four locations. The first Platterkloof Natural Heritage Site, is a servitude for a powerline linking Cape Town to South Africa’s Nuclear Power station Koeberg. This is a corridor area of 200 m by 2.6 km and between 500 and 1000 plants remain here. There is ongoing decline in the number of mature individuals taking place as the land owner, Eskom, are reticent to burn the site in fear of damaging powerlines. This same subpopulation also has stands of individuals occurring at Bothasig common and at the military base Fort iKapa formally known as 6BOD at both these sites between 50 and 100 plants remain. The nearby road fragment of the N1-N7 interchange had 200 plants in the year 2000 but the number of plants here have declined to fewer than five. The remaining two subpopulations occur on isolated small fragments of vegetation, the first is the Haasendal Nature Reserve in Kuilsriver where fewer than 10 plants occur and the second, at Boshof Circle, is a fragment in the industrial area of Epping on the Cape Flats. Between 10 and 20 plants remain at this location. This species has been reintroduced to another remnant of suitable habitat, the Rondebsosch common, and this subpopulation has successfully reproduced once. Reintroduction attempts to augment the subpopulation at Haasendal Nature Reserve took place in 2018 but have so far not been successful. Since 1980 six subpopulations have gone extinct each of these consisted of around 100 plants, these subpopulations occurred at the following sites: Penhill, Faure; Bellvue Farm; Scottsdene in Kraaifontein; The old Kraaifontein Forest Reserve; Old Bothasig disposal site; and the N7 road verge. An ongoing decline to the population is taking place and only one tiny subpopulation is protected at the Haasendal Nature Reserve, all other sites are not protected and are subject to multiple pressures.
|
Population trend | Decreasing |
Conservation |
| It occurs in two Natural Heritage Sites: 6BOD and Plattekloof, neither of which have an implemented fire-management plan. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Serruria aemula Salisb. ex Knight | CR A2c; B1b(i,ii,iii,iv,v)c(iv) | Raimondo et al. (2009) | | Serruria aemula Salisb. ex Knight | Endangered | Hilton-Taylor (1996) | | Serruria ciliata R.Br. (in part) | 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., 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. & van der Merwe, J. 2020. Serruria aemula Salisb. ex Knight. National Assessment: Red List of South African Plants version . Accessed on 2025/05/13 |
Comment on this assessment
