Annual. Culms single or tufted, 15–45 cm tall, 1–2.5 mm in diam., 3–4-noded. Leaf sheaths compressed, glabrous, along summit with long deciduous hairs; ligules a line of hairs; leaf blades usually involute or plicate, 6–12 × 0.2–0.3 cm. Panicle 6–15 × 3–5 cm; branches solitary, clustered, or verticillate, glabrous in axils. Spikelets gray-green, 3–5 × ca. 2 mm, 3–10 florets, with pedicels 1–5 mm. Glumes 1-veined, lower glume ca. 1.5 mm, upper glume ca. 2 mm. Lemma broadly ovate, apex acute, lower lemma ca. 2 mm. Palea ca. 1.5 mm, 2-keeled, along keels ciliate, persistent or tardily deciduous. Stamens 3; anthers ca. 0.5 mm. Caryopsis red-brown, ca. 1 mm. Fl. and fr. Jul–Nov.