Rigid Muggiegrass

Taxonomy
Scientific Name
Adenogramma rigida (Bartl.) Sond.
Higher Classification
Dicotyledons
Family
MOLLUGINACEAE
Synonyms
Pharnaceum rigidum Bartl., Psammotropha rigida Fenzl
Common Names
Rigid Muggiegrass (e)
National Status
Status and Criteria
Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C2a(i)
Assessment Date
2015/02/04
Assessor(s)
N.A. Helme, D. Raimondo & L. von Staden
Justification
A rare, range-restricted species, thought to be extinct until a few small subpopulations were recently discovered on the Cape Flats and Cape Peninsula. Its current Extent of Occurrence is 365 km², and four remaining locations are known. The population of less than 500 mature individuals consists of small subpopulations, numbering fewer than 200 mature individuals, and continues to decline due to ongoing habitat loss and degradation, and competition from alien invasive plants.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Darling to Houwhoek.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Swartland Granite Renosterveld, Peninsula Sandstone Fynbos, Kogelberg Sandstone Fynbos, Hangklip Sand Fynbos, Cape Flats Sand Fynbos, Atlantis Sand Fynbos, Hopefield Sand Fynbos, Leipoldtville Sand Fynbos, Swartland Alluvium Fynbos
Description
Sandy flats.
Threats
Urban expansion and crop cultivation is likely to have caused the loss of all historically known subpopulations of this species. A recently discovered subpopulation is protected within the Table Mountain National Park, however, careful management of tracks around the population is required to prevent habitat loss to erosion. Other remaining subpopulations discovered in the past two years are threatened by ongoing habitat loss and degradation due to urban expansion and competition from dense, unmanaged infestations of alien invasive plants.
Population

Recent field surveys confirmed the existence of four subpopulations, the largest consisting of about 200 plants. All known subpopulations are small, and it is estimated that the population numbers fewer than 500 mature individuals, and continues to decline.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Adenogramma rigida (Bartl.) Sond.Critically Endangered (Possibly Extinct) Raimondo et al. (2009)
Bibliography

Adamson, R.S. 1955. The South African species of Aizoaceae I. Adenogramma and Polpoda. Journal of South African Botany 21:83-95.


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.


Citation
Helme, N.A., Raimondo, D. & von Staden, L. 2015. Adenogramma rigida (Bartl.) Sond. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2024/02/23

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Distribution map

© C. Merry

© C. Merry

© N.A. Helme

© N.A. Helme


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