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Scientific Name | Diastella thymelaeoides (P.J.Bergius) Rourke subsp. meridiana Rourke |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Common Names | Hangklip Silkypuff (e) |
National Status |
Status and Criteria | Near Threatened B1ab(iii)+2ab(iii) |
Assessment Date | 2020/04/20 |
Assessor(s) | A.G. Rebelo, H. Mtshali & L. von Staden |
Justification | Diastella thymelaeoides subsp. meridiana has a very restricted range, and has an extent of occurrence (EOO) and an area of occupancy (AOO) of 92 km². It is known from between 10 and 12 locations. The population is experiencing ongoing decline due to competition from alien invasive plants present inside and outside protected areas. Other threats include inappropriate fire management, road construction, fire-related population fluctuations and invasive alien ants. It therefore qualifies for listing as Near Threatened under criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This subspecies has a limited distribution in the southern Kogelberg, Western Cape Province, South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Kogelberg Sandstone Fynbos |
Description | It is found on sandstone slopes in montane fynbos, 0-600 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 germinate following fire. It is pollinated by insects. |
Threats |
| A very small proportion (2%) of this subspecies' habitat has been lost to coastal development between Rooiels and Pringle Bay in the past. However, as most of the remaining habitat is protected, this threat has ceased. Currently, it is threatened by increasing densities of alien invasive plants, especially for subpopulations that occur outside the reserve areas, and inappropriate fire management.
An additional threat is from invasive ant species that are displacing native ant species. Invasive ants do not perform the function of indigenous ants, which is to bury this subspecies' 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 |
This subspecies occurs as isolated patches of a few dozen plants. Development rapidly reduced the populations in the Pringle Bay and Rooiels urban areas in the past. Currently, more than 70% of subpopulations are protected, but are likely to be outcompeted by alien invasive plants, mostly outside the protected area. Population reduction is inferred from a decline of habitat quality.
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Population trend | Decreasing |
Conservation |
| It is present at Kogelberg and Brodie Link Nature Reserves. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Diastella thymelaeoides (P.J.Bergius) Rourke subsp. meridiana Rourke | VU A3c+4c | Raimondo et al. (2009) | | Diastella thymelaeoides (P.J.Bergius) Rourke subsp. meridiana Rourke | Rare | Hilton-Taylor (1996) | |
Bibliography |
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical 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. 1980 - unpublished. Taxonomic revision of the genus Lonchostoma.
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. Diastella thymelaeoides (P.J.Bergius) Rourke subsp. meridiana Rourke. National Assessment: Red List of South African Plants version . Accessed on 2025/04/13 |
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