Bromus arizonicus (Shear) Stebbins

Family: Poaceae, Tribe: Bromeae

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)

Arizona brome

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelets solitary, pedicelled, consisting of 5–8 fertile florets with similar-looking though diminished sterile florets at apex, elliptic to lanceolate, strongly laterally compressed, 18–30 mm long, disarticulating below each fertile floret at maturity.

Glumes persistent, lanceolate, shorter than spikelet, membranous, thinner than fertile lemma, keeled, surface glabrous or puberulous, apices acuminate. Lower glume 8–12.5 mm long, 0.8–0.9 length of upper glume, 3-veined. Upper glume 9.5–14 mm long, same length as adjacent fertile lemma, (5)7-veined, upper margins ciliolate.

Fertile florets: rachilla persistent, callus short, blunt to pointed.

Lemma ovate to lanceolate, 9.5–15 mm long, herbaceous, strongly keeled, 7-veined, midvein and lateral veins ribbed, surface glabrous or pilose, if marginal hairs present they are longer than those elsewhere, apex acute, entire or bifid, teeth 0.7–2 mm long, awn subapical, 6–15 mm long, sometimes slightly bent.

Palea same length as lemma (excluding lemma teeth).

Caryopsis elliptic to lanceolate, ca. 7–8 mm long x ca. 1 mm wide, brown, apex fleshy and hairy, hilum linear, same length as caryopsis.

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)