GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Bromus exaltatus

HABIT Perennial. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms geniculately ascending; 45–80 cm long; 2 mm diam. Culm-internodes hollow; distally glabrous, or pilose; with reflexed hairs. Lateral branches lacking. Leaf-sheaths pilose; with reflexed hairs. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades 10–30 cm long; 3–7 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy adaxially. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle 10–12 cm long; glabrous.

Panicle open; lanceolate; nodding; 10–22 cm long. Primary panicle branches 1–3 -nate; 5–11 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 5–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 25–32 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 5–11.5 mm long; 0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 8.5–14 mm long; 0.75 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 12–17 mm long; chartaceous; purple and yellow; bordered with last colour; without keel; 5 -veined. Lemma surface pubescent; hairy below. Lemma margins ciliate. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn subapical; 2.5–4 mm long overall. Palea 8.7–10.5 mm long. Palea keels scabrous. Palea surface glabrous, or puberulous; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 2.2–2.8 mm long; yellow. 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. South America: Mesoamericana.

NOTES Bromeae. Fl Costaric 1993.

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