Common name
Australian Rice
Australian Wild Rice
Perennial Wild Rice

Derivation
Oryza L., Sp. Pl. 333 (1753); Latinized from the Arabic uruz (rice), whence Greek oruza (rice) is also derived.

australiensis- from Australia.

Published in
Biblioth. Bot. 85: 333 (1815).

Habit
Annual or perennial, tufted. Rhizomes elongated, scaly. Stolons present. Basal leaf sheaths papery, pallid. Culms erect, 100–220(–300) cm tall, 4–8 mm diam. Mid-culm nodes constricted, pallid or brown. Leaf-sheaths narrower than blade at the collar, smooth, glabrous on surface. Leaf-sheaths outer margin glabrous. Leaf-sheath auricles absent (sometimes subauriculate). Ligule an eciliate membrane, 2–3 mm long, entire (often split), truncate or obtuse. Leaf-blades 10–35 cm long, 3–14 mm wide. Leaf-blade surface scaberulous or scabrous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

Inflorescence
Inflorescence compound, a panicle. Peduncle smooth. Panicle open, lanceolate or elliptic, 18–50 cm long. Primary panicle branches ascending. Panicle branches angular, scabrous, hispid.

Spikelets
Spikelets solitary. Pedicels linear, angular, scabrous, ciliate or setose, tip cupuliform, bibracteate. Fertile spikelets at least 3-flowered, comprising 1 fertile floret, without rhachilla extension, oblong, laterally compressed, compressed strongly, rostrate, 6–8.4 mm long, falling entire. Spikelet callus glabrous, base truncate.

Glumes
Glumes two. Lower glume 0.3–0.7 mm long. Upper glume 0.3–0.7 mm long.

Florets
Basal sterile florets 2 or more, similar, without significant palea. Lemma of lower sterile floret lanceolate or ovate, 1.4–2.2 mm long, 10% of length of spikelet, herbaceous, 1-keeled (slightly), 1-nerved, without lateral nerves, glabrous, acute. Lemma of upper sterile floret lanceolate, 1.4–1.6 mm long, 100% of length of lower sterile floret, herbaceous, acute. Fertile lemma oblong, laterally compressed, oblong in profile, 6–8 mm long, coriaceous or indurate, 5-nerved, several-nerved. Lemma midnerve hispid (short). Lemma lateral nerves prominent. Lemma surface scabrous, hispidulous. Lemma margins involute, ciliolate. Lemma apex caudate, 1-awned. Median (principal) awn flat below, 5–30 mm long overall, 15–55 mm long. Palea oblong, 6–8 mm long, 100% of length of lemma, coriaceous or indurate, thinner on margins, 3-nerved, without keels. Palea surface scabrous, pubescent. Palea apex acuminate. Lodicules 2, lanceolate or elliptic or ovate, membranous. Anthers 6, 3.2–5 mm long. Stigmas 2, yellow. Grain oblong, laterally compressed, 4.7–6.4 mm long. Disseminule comprising a floret.

Continental Distribution:
Australasia.

Australian Distribution:
Western Australia, Northern Territory, Queensland.

Western Australia: Gardner, Dampier. Northern Territory: Victoria River, Central Australia North. Queensland: Cook, Burke, North Kennedy.

Classification. (GPWG 2001):
Ehrhartoideae: Oryzeae

Notes
Endemic. Growing in water, swamps or seasonally inundated areas, often in black or grey clays. Flowers Mar.–Aug.