Bothriochloa alta

HABIT Perennial; caespitose. Culms erect; 75–150 cm long. Culm-internodes distally glabrous. Culm-nodes bearded. Lateral branches lacking, or sparse. Leaf-sheaths glabrous on surface. Ligule a ciliolate membrane; 2–4 mm long. Leaf-blades 20–40 cm long; 5–10 mm wide. Leaf-blade surface glabrous; hairless except near base.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; borne along a central axis; ascending; 2–4 cm long. Central inflorescence axis 5–14 cm long. Rhachis fragile at the nodes; flattened; villous on margins. Rhachis hairs 4–6 mm long. Rhachis internodes linear. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; with a translucent median line (also present in internodes); villous; with 4–6 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; lanceolate; 3–3.6 mm long. Companion sterile spikelet glumes 5 -veined.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 4.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume ovate; 1 length of spikelet; cartilaginous; without keels; keel-less except near apex. Lower glume lateral veins obscure. Lower glume surface flat; pitted; pilose; hairy below. Upper glume lanceolate; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 2 mm long; hyaline. Fertile lemma linear; hyaline; without keel. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, western South America, Brazil, and southern South America.

NOTES Andropogoneae. Fl Meso-Am 1995.

ADDITIONAL CHARACTERS Translucent line wider than sides.

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