The smooth, dark reddish-brown to orange-brown seeds resemble a nut, and are oblong to narrow and ovaloid in shape.

[6] The species is found particularly in Western Australia, Queensland, New South Wales, Tasmania, and Victoria,[7] where it is native to areas such as the Gippsland plain, Wilsons Promontory, and Highlands-Southern Fall bioregions.

Past records in Victoria show it at only two possible sites: the Gembrook-Beenak area, and the northern part of Wilsons Promontory.

[5] Gahnia rodwayi, a small, grass-like plant found in the dry forests in the southeast of Tasmania,[5] generally flowers between October and January.

Gahnia grandis is widespread in all regions of Tasmania except the midlands and the northeast, growing in poorly-drained soil types from sea-level to the mountains.

It is also found on the margins of wetlands and forests, in riparian areas on button grass heaths, and along road cuttings and ditches.

The nuts were pounded and ground into flour to make bread, and the young bases of plants growing in wetter locations may be eaten.

The plants provide safe habitat for nesting birds, butterflies, caterpillars and other insects and animals, including threatened species like the eastern barred bandicoot.

[9] With financial support from the World Wide Fund for Nature (WWF), in late 2007 the Hobart City Council, the Threatened Species Network (TSN), the Tasmanian Parks and Wildlife Services, and the Tasmanian Department of Primary Industries and Water released a primary school education package and organized a teacher training workshop aimed at encouraging community participation in efforts for the conservation of the eastern barred bandicoot.

[10] Gahnia grandis tolerates damp soil, drought, full sun or shade, and moderate frost up to −4 °C (25 °F), allowing use in various locations.

[11] This species is also planted along roadsides, and surrounding farmland, as a natural protective boundary for marsupials and to provide insect habitat.

Gahnia grandis is a very hardy, perennial grass species with woody rhizomes, which forms large tussocks.

Cutting grass is dependent for seed dispersal on birds such as the currawong,[8] which eat the fruit then regurgitate the partially-digested hard inner nut.

[citation needed] Cutting grass is also a key habitat species for the rare and threatened Burnie burrowing crayfish (Engaeus yabbimunna).