Bromus arizonicus

HABIT Annual. Culms 30–70 cm long. Leaf-sheaths glabrous on surface, or pilose. Ligule an eciliate membrane. Leaf-blades 2–5 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 10–25 cm long. Primary panicle branches appressed, or ascending.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 5–8 fertile florets; with diminished florets at the apex. Spikelets elliptic; laterally compressed; compressed strongly; 25–30 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 0.8–0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume surface glabrous, or puberulous. Lower glume apex acuminate. Upper glume lanceolate; 1 length of adjacent fertile lemma; membranous; 1-keeled; 5 -veined. Upper glume surface glabrous, or puberulous. Upper glume margins ciliolate. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 11–15 mm long; herbaceous; keeled; 7 -veined. Lemma surface glabrous, or pilose. Lemma apex dentate; 2 -fid; with lobes 0.7–2 mm long; acute; awned; 1 -awned. Principal lemma awn subapical; 7–15 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex; apex fleshy. Hilum linear.

DISTRIBUTION North America: southwest USA and south-central USA.

NOTES Bromeae. Gr Texas 1997.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.