Derivation
Austrodanthonia H.P.Linder, Telopea 7: 269 (1997); from the Latin australis (southern), thus the southern Danthonias.

racemosa- from the Latin racemus (stalk of a cluster of grapes) and -osa (abundance), referring to the racemose inflorescence.

Published in
Telopea 7: 273 (1997).

Common synonyms
Danthonia racemosa R.Br.
Notodanthonia racemosa (R.Br.) Zotov
Rytidosperma racemosum (R.Br.) Connor & Edgar
Danthonia racemosa R.Br. var. obtusata F.Muell. ex Benth.
Notodanthonia racemosa (R.Br.) Zotov var. obtusata (F.Muell. ex Benth.) Veldkamp
Rytidosperma racemosa (R.Br.) Connor & Edgar var. obtusatum (F.Muell. ex Benth.) Connor & Edgar

Habit
Perennial, tufted. Young shoots extravaginal. Culms erect, 16–60 cm tall, 3–4-noded. Mid-culm nodes glabrous. Leaf-sheaths glabrous on surface or hirsute, with tubercle-based hairs. Ligule a fringe of hairs, 0.25 mm long. Leaf-blades involute, 5–15 cm long, 1–2 mm wide. Leaf-blade surface scabrous, glabrous or pilose, with tubercle-based hairs.

Inflorescence
Inflorescence solid, a panicle. Panicle open, linear, equilateral, 5–15 cm long. Primary panicle branches indistinct the panicle almost racemose. Panicle axis scabrous.

Spikelets
Spikelets solitary. Pedicels scabrous. Fertile spikelets many flowered, comprising 4–10 fertile florets, with diminished florets at the apex, cuneate, laterally compressed, 7.5–18 mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret. Floret callus elongated, 1.5–2 mm long, pubescent.

Glumes
Glumes persistent, similar, thinner than fertile lemma. Lower glume lanceolate, 6.3–16 mm long, equalling upper glume, membranous, much thinner on margins, 5–7-nerved. Lower glume surface asperulous, rough on nerves. Lower glume apex truncate or acute. Upper glume lanceolate, 7–16 mm long, 90–130% of length of adjacent fertile lemma, membranous, with hyaline margins, 5–7-nerved. Upper glume surface asperulous, rough on nerves. Upper glume apex truncate or acute.

Florets
Fertile lemma oblong, 2–3.5 mm long, chartaceous, pallid, glossy, 9-nerved. Lemma surface with a transverse fringe of hair and with marginal hair tufts (above, with or without dorsal tufts). Lemma apex lobed, 2-fid, with oblong lobes, with lobes 5–6 mm long, acute, incised 60% of lemma length, 1-awned or 3-awned. Median (principal) awn from a sinus, geniculate, 14 mm long overall, 6–14.5 mm long, with a twisted column. Column 4 mm long. Lateral lemma awns absent or present, arising on apex of lobes, 7 mm long. Palea elliptic, 4–5 mm long. Palea keels ciliolate. Palea surface glabrous or pilose, hairy on flanks, hairy below. Palea apex emarginate or obtuse. Apical sterile florets resembling fertile though underdeveloped. Lodicules 2, fleshy, ciliate. Anthers 3, 0.4–2.3 mm long. Grain with adherent pericarp, obovoid, 1.6–2.5 mm long.

Continental Distribution:
Australasia.

Australian Distribution:
Western Australia, South Australia, Queensland, New South Wales, Victoria, Tasmania.

Western Australia: Drummond, Dale, Menzies, Warren. South Australia: Nullabor, Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South-eastern. Queensland: Burnett, Darling Downs, Moreton, Warrego. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes. Victoria: Wimmera, Wannon, Grampians, Riverina, Midlands, Victorian Volcanic Plain, Otway Plain, Otway Range, Eastern Highlands, Gippsland Plains, Gippsland Highlands, Wilsons Promontory, Snowfields, East Gippsland. Tasmania: Furneaux Group, North East, Midlands, Ben Lomond, East Coast, South West.

Classification. (GPWG 2001):
Danthonioideae: Danthonieae

Notes
Native. Widespread in south-eastern Australia, from Southern Queensland, Adelaide and Tasmania to SW W.A., altitude 0–1600 m, common in disturbed habitats, where it can be locally common, usually in lightly shaded habitats, often found under trees, occasionally in full sun. Flowers Oct. to Dec.

There are two varieties:

Austrodanthonia racemosa (R.Br.) H.P.Linder var. racemosa

Austrodanthonia racemosa (R.Br.) H.P.Linder var. obtusata (F.Muell. ex Benth.) H.P.Linder

This morphological variant is given formal recognition, as it may well form a monophyletic group: it is geographically restricted to the northern part of NSW and the southern corner of Queensland, the plants investigated were all apomictic, and morphologically quite strikingly different.

Lemmas and paleas (line drawing)
© Vickery 1956