Baumea tetragona (Labill.) S.T.Blake

Square Twig-rush

Contr. Queensland Herb. 8: 30 (1969) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Perennial with long rhizome. Culms rigid, nodeless or 1-noded, terete to irregularly 4-angled, striate, glabrous, smooth or occasionally finely scabrous near apex, 25–100 cm high, 1.3–2 mm diam. Leaves basal; blade 4-angular (often square) in cross-section (rarely narrowly rhomboid), faces often concave, scabrous to smooth, shorter and broader than culm, to 3 mm diam.; sheath pale brown, usually with reddish tinges, dull. Inflorescence ovate in outline, erect, mostly 7–15 cm long, 2–3 cm diam.; lowest involucral bract much shorter than inflorescence. Spikelets numerous, 1-flowered, 3.5–4.0 mm long; glumes 3–5, acute to long-acute, mucronate, ± excurved, very dark red-brown, margins ciliate; fertile glumes c. 4 mm long. Nut obovoid to ellipsoid, with longitudinal and short incomplete transverse ridges, faintly white-papillose between ridges, minutely hispid or papillose at apex, dull, pale brown, 1.8–2.6 mm long, 0.9–1.3 mm diam. Flowers spring–summer.

CVU, DunT, EGL, EGU, GipP, Glep, Gold, GGr, HNF, HSF, LoM, OtP, Strz, VVP, WPro, Wim. Also SA, Qld, NSW, Tas. Locally common along lowland streams and in swamps fringing heathland or heathy woodland. Sometimes occurring with B. rubiginosa.

Source: Wilson, K.L. (1994). Cyperaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons. Inkata Press, Melbourne.
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Lilianae
order Poales
family Cyperaceae
genus Baumea
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Baumea tetragona in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Baumea tetragona in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Lowan Mallee present native
Wimmera present native
Glenelg Plain present native
Victorian Volcanic Plain present native
Gippsland Plain present native
Otway Plain present native
Goldfields present native
Central Victorian Uplands present native
Greater Grampians present native
Dundas Tablelands present native
East Gippsland Lowlands present native
East Gippsland Uplands present native
Wilsons Promontory present native
Highlands-Southern Fall present native
Highlands-Northern Fall present native
Strzelecki Ranges present native

State distribution

Distribution map
South Australia
New South Wales
Australian Capital Territory