Overberg Sceptre

Taxonomy
Scientific Name
Paranomus bolusii (Gand.) Levyns
Higher Classification
Dicotyledons
Family
PROTEACEAE
Synonyms
Nivenia crithmifolia R.Br., not Paranomus crithmifolius Salisb. ex Knight
Common Names
Overberg Sceptre (e)
National Status
Status and Criteria
Near Threatened B1ab(iii)+2ab(iii)
Assessment Date
2020/05/12
Assessor(s)
A.G. Rebelo, H. Mtshali & L. von Staden
Justification
Paranomus bolusii is a range-restricted species with an extent of occurrence (EOO) of 1303 km², and an area of occupancy (AOO) of 404 km². It is however locally abundant, and still persists at between 13 and 16 locations. A continuing decline is inferred from increasing competition from alien invasive plants, and therefore this species nearly meets the criteria thresholds for Vulnerable under criterion B.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species is endemic to the Western Cape, South Africa, where it occurs from the Groenland to Kleinrivier Mountains.
Habitat and Ecology
Major system
Terrestrial
Major habitats
South Sonderend Sandstone Fynbos, Overberg Sandstone Fynbos, Kogelberg Sandstone Fynbos, Greyton Shale Fynbos, Elgin Shale Fynbos, Elim Ferricrete Fynbos, Western Coastal Shale Band Vegetation
Description
It grow in sandstone fynbos and on shale bands, at 20-840 m. 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
This species' preferred habitat is ideally suited for agriculture, particularly fruit orchards, and outside protected areas, there is ongoing habitat loss to agricultural expansion in the lowland areas, with 3% habitat loss recorded between 1990 and 2014. Paranomus bolusii has also lost habitat to gravel mining. Alien invasive plants, particularly escaped Pinus, Acacia and Eucalyptus species continue to spread and increase in Groenlandberg, Caledon Swartberg as well as parts of the Kleinrivier Mountains. If these are not controlled, they are likely to increase rapidly over the next 15-20 years to such densities that this species is likely to be outcompeted.
Population

Paranomus bolusii extends over a 47 km-long range, many of its lowland subpopulations on silcretes and shales have been decimated. However, it is still extremely abundant at higher altitudes, primarily on sandstone. Over 100 subpopulations are known, and only 14 of these are small and isolated. The population continues to decline due to habitat loss and degradation.


Population trend
Decreasing
Conservation
It is present at Groenlandberg, Houwhoek, and Caledon Nature Reserves, and Witdraai Private Nature Reserve.
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Paranomus bolusii (Gand.) LevynsVU A2cRaimondo 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.


Citation
Rebelo, A.G., Mtshali, H. & von Staden, L. 2020. Paranomus bolusii (Gand.) Levyns. National Assessment: Red List of South African Plants version . Accessed on 2025/04/29

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Distribution map

© N.A. Helme

© C. Paterson-Jones


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