Echinochloa oryzoides (Ard.) Fritsch

Family: Poaceae, Tribe: Paniceae

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)

early watergrass

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelets occurring in pairs, with disarticulation at base of each spikelet. Spikelet sessile, ovate, dorsally compressed, plano-convex (D-shaped in profile), 3.7–7 mm long x 1.9–2.5 mm wide, consisting of 1 fertile floret and 1 basal sterile floret without rachilla extension.

Glumes dissimilar, ovate, membranous, without keels. Lower glume 0.9–2.8(4) mm long (0.3–0.4 length of spikelet), enwrapping base of spikelet, 3–5-veined, surface hispid, apex cuspidate. Upper glume subequal to spikelet, 5-veined, surface hispidulous with bristly hairs on veins, apex acuminate.

Sterile lemma similar to upper glume (membranous), ovate, same length as spikelet, 5-veined, surface hispid, apex acuminate, awnless or awned from tip of lemma, 0–50 mm long. Sterile palea subequal to sterile lemma, hyaline.

Fertile lemma elliptic to ovate, dorsally compressed, convex in profile, 3.5–5 mm long, indurate, glabrous, shiny, greenish, without keel, 5-veined, margins involute, apex acute to cuspidate, laterally pinched, slightly withered.

Fertile palea subequal to fertile lemma, indurate, reflexed at apex.

Caryopsis round to oblong, dorsally compressed, 1.9–3(3.5) mm long x ca. 2 mm wide, light brown, embryo 0.7–0.85 length of caryopsis, hilum ± round, dark.

Similar Species

Similar Species Comparison Chart

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)