Leaves with auricles often present, sometimes 1-sided, grading into a usually membranous ligule; blade rolled or folded in bud, convolute, terete or flat, usually scabrous or hairy.
Inflorescence an open or contracted panicle, axis persistent or falling as a whole.
Spikelets borne singly, pedicellate, disarticulating above the glumes; 1 bisexual floret. Glumes unequal or equal, 1–5-nerved, longer than the floret; a long- or short-bearded callus at the base of each floret. Lemma terete, hardened, with convolute or involute margins enclosing the palea, usually 5-nerved, with or without 2 minute lobes, awned from the tip or between the lobes; awn with a once or twice geniculate twisted column and a straight or curved bristle. Palea membranous, 0–2-nerved, longer or shorter than the lemma. Lodicules 3 or 2.
Many species are important components of native pastures. The 'seeds' (diaspores) frequently penetrate the skin, mouths and eyes of stock, causing discomfort and resulting in lack of condition of stock as well as downgrading the value of the meat. The 'seeds' with awns and calluses also contaminate wool. Key based on Vickery et al. (1986).
| | Key to the species | |
| 1 | Panicle pyramidal when mature and spreading, with whorled branches, the branches and pedicles plumose with fine hairs mostly 0.5 mm or longer | 2 |
| Panicle linear-cylindrical to ovate-cylindrical, the branches and pedicels glabrous, scabrous or pubescent with most hairs less than 0.3 mm long | 3 |
| 2 | Branches of the panicle plumose with hairs 1.5–2 mm long; culms glabrous; glumes pilose on the nerves, scabrous between the nerves | Austrostipa elegantissima |
| Branches of the panicle plumose with hairs c. 0.5 mm long; culms pubescent around the nodes; glumes scabrous overall
Back to 1 | Austrostipa tuckeri |
| 3 | Culms branched | 4 |
| Culms not branched
Back to 1 | 7 |
| 4 | Callus ± 0.5 mm long, sharp; palea more than 60% the length of the lemma | 5 |
| Callus ± 0.5 mm long, blunt; palea ± 60% the length of the lemma
Back to 3 | 6 |
| 5 | Bristle quite flattened, distinctly broader at its base than the column, strongly curved; column scabrous | Austrostipa platychaeta |
| Bristle round-triangular in cross section, as broad as or narrower at the base than the column, straight; column pubescent
Back to 4 | Austrostipa acrociliata |
| 6 | Lemma glabrous, 1.8–2.5 mm long | Austrostipa ramosissima |
| Lemma with scattered, short, white hairs 2.7–4 mm long
Back to 4 | Austrostipa verticillata |
| 7 | Lemma with acute, hairy lobes 1.5–3 mm long at the apex; leaves pungent-pointed; coastal species | Austrostipa stipoides |
| Lemma with lobes absent or less than 0.8 mm long; leaves not pungent pointed; habitats various
Back to 3 | 8 |
| 8 | Awn falcate, the bristle curved | 9 |
| Awn twice bent or almost straight, the bristle straight
Back to 7 | 15 |
| 9 | Awn long-pubescent or plumose with spreading hairs, most of which are 0.25–0.8(–1.5) mm long | 10 |
| Awn scabrous or puberulous with appressed hairs, most of which are ± 0.2 mm long
Back to 8 | 11 |
| 10 | Leaves with blade 2–6 mm wide (0.8–2 mm diam. if rolled), scabrous to hirsute | Austrostipa drummondii |
| Leaves with blade usually rolled, 0.3–0.6 mm diam., densely hirsute
Back to 9 | Austrostipa trichophylla |
| 11 | Bristle strongly flattened, broader at its base than the column; rhizomatous | Austrostipa platychaeta |
| Bristle round-triangular in cross section, as broad as or narrower at the base than the column; not rhizomatous
Back to 9 | 12 |
| 12 | Leaves coarse: sheaths (3–)4.5–9 mm wide; blades 1–3 mm wide, rolled and erect or expanded and flexuous | 13 |
| Leaves fine; sheaths 2–5 mm wide; blades 0.6–1.2 mm wide, rolled
Back to 11 | 14 |
| 13 | Panicle contracted, usually dense; innovations mostly intravaginal; nodes mostly concealed by the sheaths | Austrostipa nitida |
| Panicle spreading, usually sparse; innovations mostly extravaginal; nodes exserted and conspicuous
Back to 12 | Austrostipa nodosa |
| 14 | Leaves with sheath softly pilose; blade with dense, long (± 0.5 mm) spreading hairs | Austrostipa trichophylla |
| Leaves with sheath glabrous, scabrous or puberulous; blade glabrous, scabrous or shortly pubescent with most hairs less than 0.5 mm long
Back to 12 | Austrostipa scabra |
| 15 | Lemma with a coma of hairs at apex | 16 |
| Coma absent
Back to 8 | 30 |
| 16 | Lemma glabrous or almost so, surface smooth and shining | Austrostipa nullanulla |
| Lemma pubescent, surface granular
Back to 15 | 17 |
| 17 | Awn 12–18 mm long; floret narrow-cylindrical, tapering to form a neck at the apex; glumes broadly acute | 18 |
| Awn ± 20 mm long; if awn as short as 20–25 mm then floret broad-turbinate to oblong-cylindrical with no neck, or glumes linear and truncate
Back to 16 | 19 |
| 18 | Caryopsis obovoid, the style base central; lemma surface more or less hairy all over though often with a bare area between the midrib and first lateral vein, especially towards the apex | Amelichloa brachychaeta |
| Caryopsis broad-obovoid or almost gibbous, the style base eccentric; lemma surface hairy along the midrib and between the outermost lateral nerves on the margins, the area between the midrib and the first lateral vein more or less glabrous
Back to 17 | Amelichloa caudata |
| 19 | Glumes acuminate, very broad and inflated around the floret, sharply narrowing at the tip; floret broad-turbinate to oblong-cylindrical; callus sturdy and strongly curved or hooked, relatively short (usually 10–30% the length of the floret); awn relatively short (usually 4.5–6.5(–8) times the length of the floret); panicle expanded, usually with long branches | 20 |
| Glumes acute or narrow-acuminate, not inflated around the floret, tapering gradually to the tip; floret cylindrical to narrow-turbinate; callus fine or sturdy, straight, only the proximal naked tip bent, relatively long (usually 25–40% the length of the floret); awn often relatively long (usually 5–)6–13 times the length of the floret); panicle contracted or expanded, usually with short branches
Back to 17 | 24 |
| 20 | Ligule 2–8 mm long, usually more than 3.5 mm long; palea with a deep adaxial central groove; lemma involute | Austrostipa setacea |
| Ligule ± 2 mm long; palea convex on the adaxial surface or only very slightly depressed between the nerves; lemma convolute
Back to 19 | 21 |
| 21 | Coma 2–5 mm long; lower leaves pubescent or hirsute | Austrostipa blackii |
| Coma ± 2 mm long; if 2 mm long then lower leaves scabrous or glabrous, not pubescent
Back to 20 | 22 |
| 22 | Mature floret fusiform; callus 0.4–1(–1.5) mm long, very short relative to the ((5.8–)6.5–8) mm long floret; ligule 0.8–1.5 mm long | Austrostipa aristiglumis |
| Mature floret oblong-cylindrical; callus 1–2.5 mm long, long relative to the (4.5–)8.5(–9.5) mm long floret; ligule 0.3–0.5 mm long (not including auricles)
Back to 21 | 23 |
| 23 | Coma 0.8–1.3 mm long; floret 4.5–6 mm long (excluding awn), gibbous with an eccentric awn; awn 25–35(–50) mm long | Austrostipa gibbosa |
| Coma (1.2–)1.4–2 mm long; floret 6–8.5(–9.5) mm long (excluding awn); awn centric, 30–60 mm long
Back to 22 | Austrostipa bigeniculata |
| 24 | Floret with a dense and obvious coma 2–3.5 mm long | 25 |
| Floret with a coma ± 1.5 mm long, often obscure
Back to 19 | 27 |
| 25 | Column of the awn villous with hairs 0.5–1 mm long | Austrostipa stuposa |
| Column of the awn scabrous or pubescent with hairs ± 0.3 mm long
Back to 24 | 26 |
| 26 | Lower glume 11–15 mm long; lemma 5.5–6.5 mm long | Austrostipa wakoolica |
| Lower glume 16–20 mm long; lemma 7–8.2 mm long
Back to 25 | Austrostipa metatoris |
| 27 | Hairs on the lemma continued evenly to the apex, white or slightly reddish brown at maturity; floret linear-cylindrical to narrow-turbinate with no neck | 28 |
| Hairs on the top 1–2 mm of the lemma abruptly shorter by c. 50% than those on the lower part of the lemma, reddish brown early in development; floret broad turbinate to broad oblong-cylindrical with a neck
Back to 24 | 29 |
| 28 | Lower glume 15–23 mm long; column of the awn villous with hairs 0.5–1 mm long; leaf sheaths usually hirsute or pubescent especially near the base; panicle 20–35 cm long | Austrostipa stuposa |
| Lower glume ± 17 mm long; column of the awn scabrous, pubescent or villous; if villous then leaf sheaths scabrous or minutely puberulous and panicle to 12 cm long; near the coast
Back to 27 | Austrostipa flavescens |
| 29 | Lower glume 8–12 mm long; column of the awn scabrous with hairs 0.05–0.1 mm long | Austrostipa puberula |
| Lower glume 15–25 mm long; column of the awn pubescent with hairs 0.2–0.4 mm long
Back to 27 | Austrostipa eremophila |
| 30 | Column of the awn pubescent to plumose with hairs more than 0.3 mm long | 31 |
| Column of the awn scabrous or puberulous with hairs less than 0.3 mm long
Back to 15 | 33 |
| 31 | Column hairs 1–4 mm long, slightly appressed, distributed mainly along the ribs and thereby appearing to spiral with the spiralling column; floret 7.5–8.5 mm long | Austrostipa mollis |
| Column hairs 0.3–1 mm long, spreading, evenly distributed round the column and therefore not appearing to spiral
Back to 30 | 32 |
| 32 | Glumes glabrous except on the nerves; awn 70–90 mm long; leaves scabrous or glabrous; floret 9–11.5 mm long | Austrostipa semibarbata |
| Glumes pubescent; awn 35–45 mm long; leaves hirsute; floret 5.5–7 mm long
Back to 31 | Austrostipa densiflora |
| 33 | Palea with a deep adaxial central groove; lemma involute; ligule usually more than 3 mm long | Austrostipa setacea |
| Palea convex on the adaxial surface; lemma convolute; ligule usually less than 3 mm long
Back to 30 | 34 |
| 34 | Lemma glabrous for varying lengths below the apex, surface often tuberculate, especially at the apex; nerves of the glumes heavily overlaid with sclerenchyma forming obvious ridges | 35 |
| Lemma pubescent overall, hairs occasionally sparser at the apex, surface smooth or granular; glume nerves visible but not raised noticeably above the glume surface
Back to 33 | 38 |
| 35 | Spikelets 8–12 per panicle; column of the awn 55–70 mm long; subalpine grass | Austrostipa nivicola |
| Spikelets more than 12 per panicle; column of the awn less than 55 mm long
Back to 34 | 36 |
| 36 | Lower glume ± 15 mm long | Austrostipa rudis |
| Lower glume ± 17 mm long
Back to 35 | 37 |
| 37 | Ligule truncate, 0.4–1 mm long; glumes truncate; lemma surface strongly tuberculate at the apex; palea 50–70% the length of the lemma, obtuse | Austrostipa pubescens |
| Ligule obtuse, 1–3 mm long; glume tips broad-obtuse and membranous; lemma surface granular; palea equal in length to the lemma, acute
Back to 36 | Austrostipa pubinodis |
| 38 | Callus ± 0.5 mm long, blunt; palea ± 60% the length of the lemma | 39 |
| Callus ± 0.5 mm long, sharp; palea equal in length to the lemma
Back to 34 | Austrostipa acrociliata |
| 39 | Lemma glabrous, 1.8–2.5 mm long | Austrostipa ramosissima |
| Lemma with scattered short white hairs, 2.7–4 mm long
Back to 38 | Austrostipa verticillata |
