Plants annual or perennial. Culms 12-155 cm, nodes glabrous, internodes solid. Ligules membranous; blades linear, narrow, usually flat. Inflorescences terminal, panicles of 5-40 racemosely-arranged, spikelike branches, exceeding the leaves; branches spreading to appressed, persistent, unilateral, with 1 spikelet per node. Spikelets 5.3-14 mm long, with 2 or more florets, typically with 2-8 bisexual florets, sterile or staminate florets sometimes present distal to the bisexual florets; rachilla internodes pilose basally, apices oblique; disarticulation above the glumes and below the florets. Glumes from shorter than to greatly exceeding the florets, equal or subequal to each other, narrow, apices acuminate and mucronate, awnlike, or awned; calluses well-developed, strigose; lemmas 3-veined, conspicuously hairy adjacent to and on the lateral veins, apices cleft, midveins excurrent from the sinuses, sometimes forming awns. x = 10. Name from the Greek thrix, hair, and neuron, nerve, alluding to the hairs on the lateral lemma veins.

Trichoneura is a genus of seven species that grow in dry, sandy, or stony soils. Five species are native to the Eastern Hemisphere and two to the Western Hemisphere, one of which is native to the Flora region.

1.   Trichoneura elegans Swallen
Silveus Grass

Plants annual; cespitose. Culms (12)30-115 cm, erect to decumbent, usually rooting at the lower nodes, mostly glabrous, pubescent beneath the panicles. Lower sheaths longer than the internodes, antrorsely scabridulous; ligules 1.2-2.7 mm, truncate, erose; blades (2.5)5-35.2 cm long, (1)2-9.3 mm wide, antrorsely scabridulous, usually flat, becoming involute or convolute when dry. Panicles (3)4-23 cm long, 1.5-8 cm wide, rachises pubescent; branches 5-24, ascending, axes triquetrous, lower branches (0.8)1-9.5 cm. Spikelets 8-11.5 mm, with 5-10 florets, distal 1-4 florets sterile or staminate. Glumes with 1 green to purplish vein, antrorsely scabridulous, apices acuminate, awnlike; lower glumes 5.9-11.5 mm; upper glumes 5.8-10.5 mm; lowest lemmas 4.5-5.7(6.4) mm, veins green, midveins excurrent to 1.2 mm, midsections hairy adjacent to and on the lateral veins, with 0.5-1.6 mm hairs, antrorsely scabridulous elsewhere; paleas 4-5 mm, antrorsely scabridulous on the apices and veins; anthers 3, 1.3-1.7 mm, yellow to purplish. Caryopses 2.6-3 mm long, 0.7-0.9 mm wide, flattened. 2n = 40.

Trichoneura elegans usually grows in dry, deep, sandy soil. Its range extends from south central Texas to northern Tamaulipas, Mexico.