Silver-ball Conebush

Taxonomy
Scientific Name
Leucadendron muirii E.Phillips
Higher Classification
Dicotyledons
Family
PROTEACEAE
Common Names
Silver-ball Conebush (e)
National Status
Status and Criteria
Near Threatened B1ab(iii)+2ab(iii)
Assessment Date
2019/08/11
Assessor(s)
A.G. Rebelo, H. Mtshali & L. von Staden
Justification
Leucadendron muirii is a range-restricted species with an Extent of Occurrence of 4081 km², and an Area of Occupancy of 700 km². It is however locally common, and still persists at more than 10 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
Leucadendron muirii is endemic to a small area of the southern coast of the Western Cape, where it occurs between Elim and Albertinia.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Canca Limestone Fynbos, De Hoop Limestone Fynbos, Agulhas Limestone Fynbos, Hartenbos Strandveld
Description
It occurs in limestone fynbos on coastal flats, 0-250 m. Mature individuals are killed by fires, and only seeds survive. Wind-dispersed seeds are stored in fire-resistant inflorescences, and released after fires. It is dioecious, with insect-pollinated male and female flowers occurring on separate plants.
Threats
About 8% of this species' habitat is already irreversibly modified, predominantly due to habitat loss to coastal development and agricultural expansion. No significant ongoing habitat loss was recorded since 1990, but sporadic, ongoing loss, particularly to coastal development between Witsand and Stilbaai, remains likely. More concerning is the fact that at least 20% of still intact limestone fynbos is densely infested with alien invasive plants that are outcompeting native species. Efforts are ongoing to clear invasive species in protected areas such as De Hoop Nature Reserve, but is proving extremely difficult due to persistent seed banks. Outside protected areas invasive plants have in many places completely replaced native species, but the impact of these invasives on the populations of native species such as L. muirii is not known due to the lack of long term monitoring data. It is a slow-maturing reseeder, and therefore potentially vulnerable to increases in fire frequency.
Population

This species has a limited distribution range, but is locally common in suitable habitat. Subpopulations are large, occurring over extensive areas. The two largest subpopulations, each numbering more than 10 000 mature individuals, occur in De Hoop Nature Reserve and between Albertinia and Stilbaai. The population trend is not known, but it is suspected to be declining.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Leucadendron muirii E.PhillipsLeast 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.


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.


Vlok, J. and Schutte-Vlok, A.L. 2010. Plants of the Klein Karoo. Umdaus Press, Hatfield.


Citation
Rebelo, A.G., Mtshali, H. & von Staden, L. 2019. Leucadendron muirii E.Phillips. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/07/10

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Distribution map

© J.H. Vlok/A.L. Schutte-Vlok


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