13. Panicum virgatum Linnaeus, Sp. Pl. 1: 59. 1753.
柳枝稷 liu zhi ji
Chasea virgata (Linnaeus) Nieuwland; Milium virgatum (Linnaeus) Lunell; Panicum giganteum Scheele; P. glaberri-mum Steudel; P. purinisum Bernhardi ex Trinius.
Perennial with scaly rhizomes. Culms tough, erect, 60–200 cm tall, usually unbranched, nodes glabrous or pubescent. Leaves basal and cauline; leaf sheaths rounded, glabrous; leaf blades linear, flat, 20–40 × 0.3–1.5 cm, glabrous, apex acuminate; ligule 1.5–7 mm, a ciliate fringe, membranous at the base. Panicle open, oblong or rhomboid in outline, 15–55 cm, the spikelets often clustered on the secondary branches. Spikelets ovate, 3–5 mm, glabrous; glumes ovate, acuminate; lower glume 2/3–3/4 length of spikelet, 5-veined; upper glume as long as spikelet, 5-veined; lower floret staminate, lemma similar to upper glume, 5–7-veined, palea well developed; upper floret pale, shiny. Fl. and fr. Jul–Oct. 2n = 21, 25, 30, 32, 36, 72.
Commonly cultivated for forage [native to North America].