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habit (Photo: Sheldon Navie)
habit with young seed-heads (Photo: Sheldon Navie)
habit with mature seed-heads (Photo: Sheldon Navie)
young seed-head with numerous branches (Photo: Sheldon Navie)
seed-head subtended by several large leafy bracts (Photo: Sheldon Navie)
close-up of mature seed-head (Photo: Sheldon Navie)
close-up of mature flower spikelets (Photo: Sheldon Navie)
young plant (Photo: Sheldon Navie)
Cyperus eragrostis Lam.
drain flat sedge, drain flat-sedge, nutsedge, pale galingale, tall flat sedge, tall flatsedge, tall umbrella sedge, tall umbrellaplant, umbrella grass, umbrella sedge
Native to USA (i.e. New Jersey, Oregon, Washington, Louisiana, Mississippi, Texas, California) and South America (i.e. Surinam, Brazi, Bolivia, Peru, Argentina, Chile and Uruguay).
Widely naturalised in southern and eastern Australia (i.e. in south-eastern Queensland, New South Wales, the ACT, Victoria, Tasmania, many parts of South Australia and south-western Western Australia).
Also naturalised on Lord Howe Island and in many other parts of the world (i.e. Europe, southern Africa, tropical Asia, New Zealand and parts of North America beyond its native range).
This sedge is an important weed of rice crops and irrigation channels and also grows in gardens, parks, disturbed sites, waste areas and damp environments (i.e. along waterways and in wetlands). It is regarded as an environmental weed in New South Wales, Victoria and Western Australia.
Drain flat-sedge (Cyperus eragrostis) appears on several local environmental weed lists in New South Wales and Victoria and has been recorded in conservation areas in these states (e.g. in Narran Lake Nature Reserve, near Lightning Ridge in inland northern New South Wales, and in John Gardiner Reserve in suburban Melbourne). In south-western Western Australia it grows in irrigated pastures, wetlands and swamps and is listed as a moderately invasive species in the Environmental Weeds Strategy of Western Australia. Drain flat-sedge (Cyperus eragrostis) is also one of several exotic weeds growing in the limited riparian areas occupied by the seriously endangered Tuggeranong lignum (Muehlenbeckia tuggeranong), along the Murrumbidgee River in the ACT.