Brachiaria jaliscana

HABIT Annual. Culms geniculately ascending; 30–120 cm long; rooting from lower nodes. Culm-internodes hollow. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths glabrous on surface; outer margin glabrous, or hairy. Ligule a ciliate membrane; 1.5–2 mm long. Leaf-blades lanceolate; 6–30 cm long; 5–20 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–12; borne along a central axis; unilateral; 3–8 cm long. Central inflorescence axis 7–20 cm long. Rhachis broadly winged; with sharp-edged midrib; 1.5–2.7 mm wide; with scattered hairs; scabrous on margins. Spikelet packing adaxial; regular; 2 -rowed. Raceme-bases glabrous.

Spikelets solitary, or in pairs. Fertile spikelets sessile and pedicelled; 1 in the cluster, or 2 in the cluster. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or elliptic; dorsally compressed; compressed slightly; acute; 4–5.5 mm long; falling entire. Rhachilla internodes elongated between glumes.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.33 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma lanceolate, or elliptic; 3.5–5 mm long; indurate; without keel. Lemma surface unwrinkled, or rugulose. Lemma margins involute. Lemma apex obtuse. Palea involute; indurate; without keels.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2–2.5 mm long.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Sant.-Michel 2004.

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