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Scientific Name | Serruria glomerata (L.) R.Br. |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Common Names | Cluster Spiderhead (e) |
National Status |
Status and Criteria | Rare |
Assessment Date | 2020/08/06 |
Assessor(s) | A.G. Rebelo, H. Mtshali & L. von Staden |
Justification | Serruria glomerata has a highly restricted distribution range, extent of occurrence (EOO) 324-325 km², and area of occupancy (AOO) 180-184 km². It is largely confined to conservation areas and is not declining at present. It has lost its lowland subpopulations in past, primarily to urban expansion on the Cape Flats. The remaining subpopulations are potentially vulnerable to alien invasive plants and ants, and too frequent fires. A subpopulation at the Kleinplaas Dam could be eliminated if the dam is enlarged. It is therefore listed as a restricted-range species under the national category of Rare. It qualifies under the IUCN criteria as Least Concern. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This species is endemic to the Cape Peninsula and Cape Flats, in the Western Cape Province of South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Peninsula Sandstone Fynbos, Hangklip Sand Fynbos, Cape Flats Sand Fynbos |
Description | It is largely confined to Peninsula Sandstone Fynbos. 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 |
| More than 40% of this species' habitat is already irreversibly modified, mainly due to historical loss to urban development in the Cape Flats. Remaining subpopulations are predominantly threatened by competition from alien invasive plants, which are being actively cleared throughout its range on the Cape Peninsula. A subpopulation at the Kleinplaas Dam could be eliminated if the dam is enlarged.
Groundwater abstraction, and drying up of wetlands due to the presence of alien invasive plants are future potential threats. Another potential threat is invasive ant species that are displacing native ant species. Invasive ants do not perform the function of indigenous ants, which is to bury this species' seeds in their nests where they are protected from fire. Large scale ant invasions could lead to population collapse if there is no soil-stored seed bank to regenerate from post fire. |
Population |
Serruria glomerata is locally common, occurring in dense subpopulations. The population is no longer declining as all remaining habitat of this species is protected.
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Population trend | Stable |
Conservation |
| All the large populations are found at the Table Mountain National Park, and the Cape Flats remnants are in the Tokai Forest and Kenilworth Race Course Core Conservation sites. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Serruria glomerata (L.) R.Br. | VU A2c | Raimondo et al. (2009) | |
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.
Helme, N.A. and Trinder-Smith, T.H. 2006. The endemic flora of the Cape Peninsula, South Africa. South African Journal of Botany 72(2):205-210.
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.
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Citation |
| Rebelo, A.G., Mtshali, H. & von Staden, L. 2020. Serruria glomerata (L.) R.Br. National Assessment: Red List of South African Plants version . Accessed on 2024/12/07 |
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