Bromus ayacuchensis

HABIT Perennial; caespitose; clumped loosely. Cataphylls evident. Rhizomes short. Basal innovations extravaginal. Culms erect; (30–)50–120 cm long. Culm-internodes distally pilose. Lateral branches lacking. Leaf-sheaths tubular for much of their length; with 0.66–0.75 of their length closed; 8–10 cm long; pilose; with reflexed hairs; outer margin glabrous. Ligule an eciliate membrane; 3–6.6 mm long; pilose on abaxial surface; erose; obtuse. Leaf-blades 20–55 cm long; 3–8 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy abaxially, or on both sides. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; obovate; loose; equilateral, or nodding; 12–26 cm long; 1–8 cm wide. Primary panicle branches ascending, or spreading, or drooping; 2–4 -nate; 1.5–10 cm long. Panicle axis scabrous; with scattered hairs, or glabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–7 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; compressed strongly; (12–)18–27 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2–3 mm long.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 5–8 mm long; 0.66 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or pilose. Lower glume apex obtuse. Upper glume lanceolate; 8–11.2 mm long; 0.8–0.9 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume surface glabrous, or pilose. Upper glume apex acute; muticous, or mucronate.

FLORETS Fertile lemma lanceolate; 10–12.6 mm long; chartaceous; keeled; 5–7 -veined. Lemma surface pubescent. Lemma hairs 0.2–0.5 mm long. Lemma apex entire, or dentate; 2 -fid; with lobes 0.2 mm long; awned; 1 -awned. Principal lemma awn apical, or from a sinus; 3–5.5 mm long overall. Palea 9–12 mm long. Palea keels ciliate. Palea apex with excurrent keel veins. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; elliptic, or obovate; 1–1.3 mm long; membranous. Anthers 3; 3.1–3.8 mm long; yellow, or orange. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; oblanceolate; 5.8–7 mm long; hairy at apex; apex fleshy. Hilum linear; 1 length of caryopsis.

DISTRIBUTION South America: western South America.

NOTES Bromeae. Saarela et al 2007.

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