Setaria viridis (L.) P. Beauv.

Family: Poaceae, Tribe: Paniceae

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

Note—Although some authors consider Setaria viridis to be synonymous with S. italica (L.) P. Beauv, we are following the Flora of North America treatment for grasses, which considers them separate taxa.

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

green foxtail

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelet subtended by fascicle of 1–3 bristles measuring 5–10 mm long, flexible, antrorsely scaberulous, glabrous, usually green, rarely purple. Disarticulation above the bristles. Spikelets clustered (2–6 per cluster), pedicelled (oblong), ovate to broadly elliptic, dorsally compressed, plano-convex (D-shaped in profile), 1.8–2.2(3.2) mm long x 0.9–1.2 mm wide x 0.8–1.0 mm thick, falling entire, consisting of one fertile floret and one basal sterile floret without rachilla extension.

Lower glume triangular-ovate to oblate, 0.7–0.9 mm long (0.25–0.33 length of spikelet), membranous, enwrapping base of spikelet, without keel, 1–3-veined, apex obtuse. Upper glume elliptic, 0.9–1 length of spikelet, membranous, without keel, 5(6)-veined, apex obtuse.

Sterile lemma similar to upper glume (membranous), oblong, same length as spikelet, 5(7)-veined, apex obtuse. Sterile palea 0.33–0.5 length of sterile lemma, hyaline.

Fertile lemma elliptic, dorsally compressed, convex in profile, 2–3 mm long, light grayish-brown, usually with satiny sheen, indurate, without keel, 3 veins light-colored, surface ridged transversely, margins involute, apex obtuse.

Fertile palea indurate, margins involute.

Caryopsis broadly elliptic, ca. 1.5 mm long x ca. 1 mm wide, greenish, embryo >0.66 length of caryopsis, hilum round.

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)