Plants perennial. Culms 30-200 cm, erect, occasionally geniculate
below, compressed, branched; internodes solid. Sheaths glabrous,
scabrous, or sparsely pilose below, hairs never papillose-based; ligules
0.3-1 mm, truncate, firmly membranous, fimbriate or erose, sometimes pilose at
the sides; blades 5-45 cm long, 4-10 mm wide, glabrous abaxially, glabrous
or sparsely pilose adaxially. Panicles 5-60 cm, with 9-25 usually racemose
(rarely subdigitate) branches; secondary panicles not present in the lower
sheaths; branches (1.5)3-18 cm, erect to spreading, somewhat flexible.
Spikelets 2.5-4 mm, imbricate to distant, with 3-6(8) florets. Lower
glumes 1.7-2.9 mm, lanceolate, acute; upper glumes 1.7-3.8 mm, lanceolate
to ovate, acute, acuminate, rarely mucronate; lemmas (1.5)2.3-3.6 mm, ovate,
chartaceous, veins sericeous, apices usually acute, rarely obtuse, unawned, mucronate,
or awned, awns to 11 mm; paleas glabrous; anthers 2, 0.2-0.5 mm.
Caryopses 1-1.8 mm long, about 0.5 mm wide, narrowly elliptic to ovate,
somewhat laterally compressed. 2n = 40.
Leptochloa virgata is a common neotropical species that extends from the
southeastern United States through the West Indies to Argentina. Awn length and
lemma pubescence vary continuously and independently, precluding their use in
recognizing additional taxa.