Bromus tectorum L.
Family: Poaceae, Tribe: Bromeae
Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)
Anisantha tectorum (L.) Nevski, Shedonorus tectorum (L.) Fries
Pertinent Common Names (particularly those used in California; go to GRIN for other common names)
cheatgrass, downy brome
Primary Disseminule Type
Description (diagnostics are in brown)
Spikelets solitary, pedicelled, consisting of 1–8 fertile florets with similar-looking though diminished sterile florets at apex, cuneate, slightly laterally compressed, 10–25(35) mm long, disarticulating below each fertile floret at maturity.
Glumes persistent, dissimilar, shorter than spikelet, chartaceous, gaping, keeled, margins hyaline. Lower glume linear, (4)6–11 mm long, 0.7–0.8 length of upper glume, 1-veined, apex acuminate. Upper glume lanceolate, 6–13 mm long, 0.7–0.8 length of adjacent fertile lemma, 3–5-veined, apex acute.
Fertile florets: rachilla persistent, 2–3 mm long, with scattered minute hairs, callus pointed, with extremely minute hairs.
Lemma elliptic to oblanceolate, sometimes slightly arched, 9–16 mm long, chartaceous, much thinner on margins, with rounded back (no keel), 5–7-veined, midvein strongly ribbed, lateral veins somewhat ribbed, surface scaberulous and glabrous or hirsute, apex acuminate, bifid, teeth 1–3 mm long, awn subapical, 8–25 mm long, straight, scabrous.
Palea 0.8 length of lemma, hyaline, keels ciliolate.
Caryopsis elliptic to linear, 6–9 mm long x 0.9–1.5 mm wide, purplish brown, apex fleshy and hairy, hilum linear, same length as caryopsis.
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)
AUQP, NZBORIC, NZBPI