Plants annual. Culms 15-41 cm. Ligules 0.5-1 mm; blades
2.5-7 cm long, 3-5 mm wide, glabrous. Panicles 4-9.5 cm long, 7-9 mm wide;
rachises pubescent; branches 0.5-1 mm, pubescent, with 2(3) spikelets,
axes not extending past the distal spikelets; proximal internodes 0.5-0.8
mm, longer than the second internodes. Spikelets bisexual; proximal
spikelets 3-3.5 mm; second spikelets 2.9-3.3 mm. Lower glumes
absent or to 0.4 mm, glabrous; upper glumes 3-3.5 mm, minutely pubescent,
7-veined; glume projections 6-9, in 7 rows, 0.1-0.6(1) mm, uncinate; lemmas
(2)2.3-2.7 mm, sparsely pubescent on the back; paleas 2.1-2.3 mm; anthers
3, 0.3-0.6 mm, yellow. Caryopses (1.2)1.4-1.6 mm long, 0.6 mm wide. 2n
= unknown.
Tragus heptaneuron is native to tropical Africa, but it has been collected
in Florence County, South Carolina.