Watergras

Taxonomy
Scientific Name
Cotula myriophylloides Harv.
Higher Classification
Dicotyledons
Family
ASTERACEAE
Common Names
Watergras (a)
National Status
Status and Criteria
Critically Endangered B2ab(iii)
Assessment Date
2013/09/16
Assessor(s)
R.F. Powell, N.A. Helme, D. Raimondo & L. von Staden
Justification
Most historic collections are from the Cape Peninsula, all of these subpopulations are now extinct due habitat loss and degradation as a result of urban expansion. There are only two localized, isolated remaining subpopulations, possibly a third, and these are severely fragmented (EOO 8786 km², AOO <1 km²). This species remains threatened by eutrophication and potential future alterations of water flow dynamics.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
Cape Peninsula to Plettenberg Bay.
Habitat and Ecology
Major system
Freshwater
Major habitats
South Outeniqua Sandstone Fynbos, Agulhas Sand Fynbos, Estuarine Functional Zone
Description
Submerged in seasonal coastal pools, but also in marshes and on wet sand. Mostly in brackish, but also fresh, still or slowly moving water.
Threats
Threatened by cattle grazing and invasive alien plants at both remaining locations, and habitat loss and degradation due to urban expansion at a possible third. Drainage of wetlands is a past threat. This species is now extinct on the Cape Flats and the Cape Peninsula due to habitat loss to urban expansion-related wetland drainage, or conversion from seasonal wetlands to permanent, eutrophic systems.
Population

Herbarium records indicate that this species was common on the Cape Peninsula in the past, but it is now locally extinct in this area. Further east along the southern Cape coast, this species is known from only three isolated, very widely separated subpopulations, scattered over an area of over 400 kilometres.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Cotula myriophylloides Harv.CR B1ab(iii)Raimondo et al. (2009)
Cotula myriophylloides Harv.VU D2Victor (2002)
Cotula myriophylloides Harv.Indeterminate Hilton-Taylor (1996)
Cotula myriophylloides Harv.Indeterminate Hall et al. (1980)
Bibliography

Cook, C.D.K. 2004. Aquatic and wetland plants of southern Africa. Backhuys Publishers, Leiden, The Netherlands.


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.


Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.


Harvey, W.H. 1894. Compositae. In: W.H. Harvey and O.W. Sonder (eds). Flora Capensis III (Rubiaceae to Campanulaceae):44-530. L. Reeve & Co., Ltd., Ashford.


Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.


Powell, R.F., Boatwright, J.S. and Magee, A.R. 2014. A taxonomic revision of the Cotula coronopifolia group (Asteraceae) and implications for the conservation statuses of the species. South African Journal of Botany 93:105-117.


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.


Sieben, E.J.J. 2009. The status and distribution of vascular plants (Magnoliophyta, Lycophyta, Pteridophyta). In: W.R.T. Darwall, K.G. Smith, D. Tweddle and P. Skelton (eds.), The status and distribution of freshwater biodiversity in southern Africa (pp. 83-98), IUCN and SAIAB, Gland, Switzerland and Grahamstown, South Africa.


Victor, J.E. 2002. South Africa. In: J.S. Golding (ed), Southern African plant Red Data Lists. Southern African Botanical Diversity Network Report 14 (pp. 93-120), SABONET, Pretoria.


Citation
Powell, R.F., Helme, N.A., Raimondo, D. & von Staden, L. 2013. Cotula myriophylloides Harv. National Assessment: Red List of South African Plants version . Accessed on 2025/04/19

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Distribution map

© N.A. Helme

© N.A. Helme


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