Perennial, dioecious, rushlike, rhizomatous herbs, glabrous or with cilia on the margins of culm, rhizome sheaths, and inflorescence bracts. Culms simple or branched, terete or flattened, smooth or finely rugose or with scabrous lateral margins towards the apex, sometimes with several nodes. Leaves persistent, basal or cauline, either well-developed with an equitant base and isobifacial lamina (and with a small ligule between the lamina and the sheathing base) or consisting primarily of a lax or tight sheath with a vestigial dorsiventral lamina. Inflorescence branching sympodially; each branch subtented by a bract (sometimes called spathe); the 2 sexes alike or dissimilar (Lyginia). Flowers not in true spikelets, sessile or pedicellate, subtended by 1 or 2 bracts. Tepals 6, in two more or less similar whorls, sometimes hidden by the bracts, rigid to scarious-membranous or hyaline, glabrous or apically ciliate. The male flowers of Lyginia have one keeled outer tepal, the other tepals more or less flat. Male flowers with 3 stamens opposite the inner tepals, filaments free or fused into a stout tapering solid column (Lyginia); anthers exserted, dorsifixed, 4-sporangiate, 2- lobed, each lobe dehiscing by a longitudinal slit; pistillode absent; pollen with graminoid-type aperture. Female flowers with or without staminodes; ovary superior, 1- or 3-locular with a solitary pendulous orthotropous ovule per locule; style with 3 papillose branches, free to the base or fused in the lower third or style unbranched, papillose. Fruit varied; either a 3-locular, 3-angled loculicidal capsule (Anarthria, Lygninia) or a small globose or elliptic unilocular diclesium (Hopkinsia).
Anarthriaceae differs from Restionaceae in having 4-sporangiate, 2-lobed anthers, opening by 2 longitudinal slits (instead of 2-sporangiate, non-lobed anthers with 1 dehiscence slit)
Most species resprout after fire. Clones some species can cover an area over 100 m across. Lyginia excelsa is an obligate seeder (Briggs and Johnson 2000).
Usually on sandy nutrient poor soils, in dry or well drained or seasonally damp heath and woodland; well drained or seasonally damp woodlands and heaths.
All members of the family are native to the south part of Western Australia.