Brachypodium mexicanum

HABIT Perennial; culms solitary, or caespitose. Culms 40–150 cm long. Culm-internodes scaberulous. Culm-nodes pubescent. Leaf-sheaths scaberulous; glabrous on surface, or puberulous. Ligule an eciliate membrane; 1–3 mm long. Leaf-blades 5–25 cm long; 1–2 mm wide. Leaf-blade surface pilose; sparsely hairy.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 2–15 cm long; bearing few fertile spikelets; bearing 2–8 fertile spikelets on each. Rhachis glabrous on surface. Spikelet packing broadside to rhachis; lax.

Spikelets ascending, or spreading; solitary. Fertile spikelets pedicelled. Pedicels oblong; 2–3 mm long.

FERTILE SPIKELETS Spikelets comprising 2–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–30 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 4.5–9 mm long; 0.66–0.75 length of upper glume; membranous; without keels; 5 -veined. Lower glume apex acute. Upper glume lanceolate; 7–11 mm long; 0.9 length of adjacent fertile lemma; membranous; without keels; 7 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 8–12 mm long; chartaceous; without keel; 7 -veined. Lemma surface scaberulous; rough above. Lemma apex obtuse, or acute; awned; 1 -awned. Principal lemma awn apical; 3–6 mm long overall. Palea 8–12 mm long. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3. Ovary with a fleshy appendage below style insertion; pubescent on apex.

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

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, and western South America.

NOTES Brachypodieae. Fl Nov Gal 1993.

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