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Scientific Name | Serruria gremialis Rourke |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Common Names | Riviersonderend Spiderhead (e) |
National Status |
Status and Criteria | Near Threatened A4ce; B1ab(iii,v)+2ab(iii,v) |
Assessment Date | 2020/07/06 |
Assessor(s) | A.G. Rebelo, H. Mtshali & L. von Staden |
Justification | Serruria gremialis has a restricted distribution range, with an extent of occurrence (EOO) of 2836 km², and an area of occupancy (AOO) of 636 km². There is continuing decline due to ongoing habitat loss and degradation. A population reduction of 21-28% is projected to be met by 2119, over a period of less than three generations for this long-lived resprouter (generation length 50-100 years), which includes two generations in the past and one generation projected into the future. It therefore nearly meets the criteria for listing as Vulnerable under criteria A and B and is listed as Near Threatened. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This species is endemic to Riviersonderend and Stettyn mountains in the Western Cape Province, South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | South Sonderend Sandstone Fynbos, North Sonderend Sandstone Fynbos, Overberg Sandstone Fynbos, Kogelberg Sandstone Fynbos, Hawequas Sandstone Fynbos, Greyton Shale Fynbos, Elgin Shale Fynbos |
Description | It grows on north-facing sandstone slopes, 270-760 m, and is a long-lived species (generation length 50-100 years) that survives fires by resprouting from an underground rootstock. 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 |
| About 21% of this species' habitat is already irreversibly modified, predominantly due to habitat loss to crop cultivation on the lowlands around Houhoek, Villiersdorp, and Riviersonderend, and loss continues, with 1% loss recorded between 1990 and 2014. It is mainly threatened by competition from alien invasive plants across most of its range. |
Population |
Serruria gremialis is found as scattered plants, in large, extensive populations. Population decline is inferred from ongoing habitat loss and degradation.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Serruria gremialis Rourke | Least Concern | 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.
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 gremialis Rourke. National Assessment: Red List of South African Plants version . Accessed on 2024/12/07 |
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