Bromus attenuatus

HABIT Perennial; caespitose. Culms erect; 100 cm long. Leaf-sheaths smooth, or scaberulous; pubescent. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 0.4 mm long. Leaf-blades 30–60 cm long; 8–16 mm wide. Leaf-blade surface scabrous. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 18 cm long. Primary panicle branches drooping; bearing 1–2 fertile spikelets on each lower branch. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 5–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 25–28 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 6.5–7.5 mm long; 0.9 length of upper glume; membranous; without keels; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 7–8 mm long; 0.6 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume primary vein scabrous. Upper glume apex obtuse.

FLORETS Fertile lemma oblong; 12–13 mm long; chartaceous; without keel; 3 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn subapical; 2–3 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: Mexico.

NOTES Bromeae. Swallen 1994.

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