Carex inversa R.Br.

Knob Sedge

Prodr. 242 (1810) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Rhizome long, or rarely short; shoots ± loosely tufted, or rarely densely tufted. Culms erect, terete, smooth, 8–50 cm long (rarely as short as 1 cm and enclosed by leaves), (0.7–)1–1.5(–2.5) mm diam. Leaves mostly shorter than culms, 0.7–2 mm wide; sheath dark brown, persisting as fibrous remains; ligule obtuse to rounded. Inflorescence erect, 0.7–3 cm long, with 2–6 spikes solitary at nodes; lowest involucral bracts exceeding inflorescence. Spikes sessile, ± contiguous, spreading to erect at maturity, to 1(–1.5) cm long; all spikes with female flowers above male flowers; glumes acuminate to obtuse, mostly short- to long-mucronate, whitish to pale yellow-brown (rarely orange-brown) with green midrib; female glumes 2–3(–5) mm long; utricles 2.2–4.5 mm long, 1.0–2.1 mm diam., broad-obovoid to ellipsoid, ± strongly several–many-nerved, sometimes transversly wrinkled between nerves, densely minutely hispid on narrowly winged margins and beak, green to yellowish; beak 0.3–1.1 mm long, with apex split; style 2-fid. Nut obovoid to broad-ellipsoid, lenticular, pale to dark yellow-brown.

CVU, DunT, EGL, EGU, GipP, Glep, Gold, GGr, HNF, HSF, LoM, MonT, MuF, MuM, NIS, OtP, OtR, SnM, Strz, VAlp, VRiv, VVP, WaP, Wim. All States (including Lord Howe Is.) except NT, also Norfolk Is. New Zealand. Naturalised in USA (California), and recorded as a casual wool alien in United Kingdom. Widespread in grassland and open forest communities from near sea-level to the subalps, uncommon to rare in the far north-west and on heavy soils of Victorian Volcanic Plain and Wimmera.

A very variable species with several forms possibly warranting formal recognition. Most forms are usually long-rhizomatous, but there is also a form that is shortly-rhizomatous and often forms dense tussocks. The utricle varies in size, rugosity, thickness of nerves and relative length of beak. Several varietal names exist, but their application is uncertain, and are hence not used here. Carex inversa is very similar, and possibly not distinct from C. paupera which may merely be a high altitude form of C. inversa. Similar to Carex lophocarpa (New South Wales, and Queensland), which differs in having an often bigger inflorescence, and a longer utricle beak. Also similar to C. resectans (a New Zealand species), from which it differs in the leaves being mostly shorter than the culms, and having longer culms which are sheathed by the leaves only at base.

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.
Updated by: Val Stajsic, 2018-06-20
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Lilianae
order Poales
family Cyperaceae
genus Carex
Higher taxa


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

State distribution

Distribution map
Western Australia
South Australia
New South Wales
Australian Capital Territory