GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Oryza australiensis

HABIT Perennial; caespitose. Rhizomes elongated; scaly. Butt sheaths papery; pallid. Culms erect; 100–180(–220) cm long; 4–8 mm diam. Culm-nodes constricted; pallid, or brown. Leaf-sheaths narrower than blade at the collar; keeled; smooth; glabrous on surface; 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 10–30 cm long; 3–10 mm wide. Leaf-blade surface scaberulous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth.

Panicle open; lanceolate, or elliptic; 20–45 cm long. Primary panicle branches ascending. Panicle branches angular; scabrous; hispid.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; angular; scabrous; ciliate (short and stiff); tip cupuliform; bibracteate.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; compressed strongly; rostrate; 6–7 mm long; falling entire. Spikelet callus glabrous; base truncate.

GLUMES Glumes both absent or obscure.

FLORETS Basal sterile florets similar; barren; without significant palea. Lemma of lower sterile floret lanceolate; 1.4–1.6 mm long; 0.2 length of spikelet; herbaceous; 1-keeled (slightly); 1 -veined; without lateral veins; acute. Lemma of upper sterile floret lanceolate; 1.4–1.6 mm long; 1 length of lower sterile floret; herbaceous. Fertile lemma oblong; laterally compressed; 6 mm long; coriaceous; keeled; 5 -veined. Lemma midvein hispid (short). Lemma surface scabrous; hispidulous. Lemma margins involute; ciliolate. Lemma apex caudate; awned; 1 -awned. Principal lemma awn flat below; 5–30 mm long overall. Palea oblong; 1 length of lemma; coriaceous; thinner on margins; 3 -veined; without keels. Palea surface scabrous; pubescent. Palea apex acuminate.

FLOWER Lodicules 2; lanceolate; membranous. Anthers 6. Stigmas 2.

FRUIT Disseminule comprising a floret.

DISTRIBUTION Australasia: Australia.

NOTES Oryzeae. TB.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.