Austrostipa is an Australian genus of grasses in the family Poaceae (order Poales), commonly known as speargrasses. The genus comprises around 65 species, predominantly endemic to temperate regions of Australia and Australasia. It was segregated from the broadly defined genus Stipa and is thought to have originated in Australia approximately 20 million years ago.\n\nPlants are perennial (rarely annual) tufted grasses of varied habit. The leaf blade is rolled or folded in bud, and may be convolute, terete, or flat, usually scabrous or hairy. Auricles are often present and grade into a membranous ligule. The inflorescence is an open or contracted panicle; each spikelet contains a single bisexual floret and disarticulates above the glumes at maturity. A characteristic feature of the genus is the hardened, terete lemma that encloses the palea within convolute or involute margins, tipped by a once- or twice-geniculate (bent) awn. At the base of each floret sits a pointed, bearded callus — a key adaptation for seed dispersal.\n\nMany species are ecologically significant as components of native pastures across southern and eastern Australia. The sharp calluses and long awns of the ripe fruits are well known for penetrating the skin, eyes, and mouths of livestock, causing welfare problems and contaminating wool. Among the more distinctive members of the genus is Austrostipa elegantissima, whose pyramidal panicle has conspicuously plumose branches, and Austrostipa semibarbata, notable for its long awns reaching 70–90 mm. GBIF recognises 61 accepted species in the genus.
Distribution
The genus is endemic to temperate Australasia, with nearly all species native exclusively to Australia. Two species — Austrostipa setacea and Austrostipa stipoides — extend to New Zealand, and Austrostipa variabilis also occurs in South Africa.
Taxonomy Notes
Austrostipa was segregated from the Old World genus Stipa and currently contains around 65 accepted species. The genus is thought to have originated in Australia approximately 20 million years ago. GBIF (2024) records 61 accepted descendants. The NSW Flora key also treats species of Amelichoa, which were similarly formerly included in Stipa, alongside Austrostipa.
Ecology
Many Austrostipa species are important components of native temperate pastures across Australia. The mature fruits bear a sharp callus and a long geniculate awn that facilitates dispersal but also poses a significant problem for livestock: the diaspores penetrate the skin, mouths, and eyes of grazing animals, causing discomfort, loss of condition, and downgrading of meat. The awns and calluses also contaminate wool fleeces.
