Oryza sativa L.

Family: Poaceae, Tribe: Oryzeae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)


Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

cultivated rice

Primary Disseminule Type

floret subtended by 2 sterile lemmas or floret alone

Description (diagnostics are in brown)

Spikelets solitary, pedicelled, broadly elliptic to oblong, laterally compressed, 6–11 mm long x 2.5–4 mm wide, consisting of 2 basal sterile florets (primarily lemmas) and 1 fertile floret, without rachilla extension. Disarticulation below the sterile floret pair.

Glumes both absent or obscure.

Basal sterile florets similar, without significant palea, lanceolate, 1.5–3(10) mm long x 0.5–1.5 mm wide, 0.25–0.5(0.9) length of spikelet, membranous.

Fertile lemma elliptic, laterally compressed, 6–11 mm long x 2–3 mm wide, coriaceous, keeled, 5-veined, surface longitudinally ridged, reticulate, glabrous or with stiff hairs to 1.5 mm long, margins involute, apex beaked (beak 0.3–1(2) mm long, rigid), typically unawned or rarely awned (awn 6–15(160) mm long, scabrous).

Fertile palea elliptic, same length as lemma, 1–1.7 mm wide, coriaceous, keeled, 3-veined, veins scabrous, apex acute to acuminate or mucronate to 0.5 mm long.

Caryopsis broadly elliptic to broadly oblong, laterally compressed, 4.5–8 mm long x 2–3.5 mm wide, longitudinally ridged, brown, tan or white.

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)