Bromus densus

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 110 cm long. Culm-internodes antrorsely scabrous. Leaf-sheaths antrorsely scabrous; glabrous on surface. Ligule an eciliate membrane; 0.5 mm long; erose. Leaf-blades 10–25 cm long; 2–3 mm wide. Leaf-blade surface scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; dense; 9.5 cm long; 2 cm wide. Primary panicle branches appressed. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 6–7 mm long; 0.66 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; 9–11 mm long; 0.66–0.75 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 12–13.5 mm long; chartaceous; without keel; 3 -veined. Lemma surface pilose; hairy below. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn subapical; 1–1.5 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.