Rhizomatous, robust, straggling perennial, herb, 0.2-2.5 m high, culms 10-15 mm diam. at base; female flowers single; plant often with large, spikelet-like galls. Sand, peat. Swamps and along stream banks.
Beard’s Provinces: South-West Province.
IBRA Regions: Esperance Plains, Jarrah Forest, Swan Coastal Plain, Warren.
IBRA Subregions: Fitzgerald, Northern Jarrah Forest, Perth, Southern Jarrah Forest, Warren.
IMCRA Regions: WA South Coast.
Local Government Areas (LGAs): Albany, Augusta-Margaret River, Busselton, Denmark, Manjimup, Murray, Nannup.
Rhizomes tufted, glabrous. Basal sheath glabrous, dull, striate. Culms semi-terete or semi-flattened, internal structure (at base of culm) hollow, glabrous, striate, not marbled, not fasciculate. Culm 650-1140 mm long. Sheaths (including blade) appressed throughout, dull, striate, glabrous. Apex finely pointed, glabrous. Dioecious (with separate male and female plants). Male and female inflorescences distinctly dissimilar, posture (male inflorescences only) More or less erect, Culms unbranched below the inflorescence. Male spikelet 4.5-5, 20-27 mm long. Subtending bract glabrous, Outer bract 4-4.3, 9-17 mm long, margins thin and translucent, Apex obtuse. Perianth hairy. 3-4.2 mm long. Inner bract hairy or glabrous, margins thin and translucent, Apex obtuse. Inner bract 3-3.8, 11-13 mm long. Filament 2.2 mm long. Anther 2-2.2 mm long. Female spikelet 15-20 mm long. Subtending bract glabrous, margins thin and translucent, Apex obtuse. Outer bract 16-18 (by misinterpretation) mm long. Perianth glabrous. Inner bracts 11-13 mm long, glabrous, margins firm and opaque, Apex acute. Style three (or three-branched). Fruit trilocular (capsule). Botanical Province South-West, IBRA Bioregions Swan Coastal Plain, Jarrah Forest or Warren.