[*] Panicle contracted, often simple; grain oval or oblong; perennial, except n. 2.
1. S. ásper, Kunth. Culms tufted (2–4° high); lowest leaves very long, rigid, rough on the edges, tapering to a long involute and thread-like point, the upper short, involute; sheaths partly or at first wholly enclosing the contracted panicle; flower much longer than the unequal lower glumes; grain oval or oblong. (Vilfa aspera, Beauv.)—Sandy fields and dry hills, especially southward. Sept.—Spikelets 2–3´´ long. Flowering glume and palet rough above, smooth or hairy below, the palet tapering upward, acute, and one half to twice longer than the glume, or else obtuse and equalled or even considerably exceeded by the glume!
2. S. vaginæflòrus, Vasey. (Pl. 7, fig. 4, 5.) Culms slender (6–12´ high), ascending; leaves involute-awl-shaped (1–4´ long); panicles simple and spiked, the lateral and often the terminal concealed in the sheaths; flowering glume and palet somewhat equal, acute, about the length of the nearly equal lower glumes, only {1/3} longer than the oval grain. (Vilfa vaginæflora, Torr.)—Barren and sandy dry fields; common, especially southward. Sept.
3. S. cuspidàtus, Torr. Erect culms and appressed leaves more slender than in the preceding; panicle exserted, very simple and narrow; spikelets smaller, the lower glumes acuminate, little shorter than the cuspidate upper one. (Vilfa cuspidata, Torr.)—Maine (on the St. John's River, G. L. Goodale); also Iowa, Minn., and common westward.
4. S. depauperàtus, Vasey. Resembling n. 3, but the culms decumbent at base and matted, the leaves short and usually widely spreading, and the lower glumes barely acute, not half the length of the upper one.—W. Minn. to Kan., and southwestward.
5. S. Virgínicus, Kunth. Culms tufted, slender (5–12´ long), often procumbent, branched; leaves convolute, rigid; palets rather shorter than the nearly equal acute glumes. (Vilfa Virginica, Beauv.)—Sandy seashore, Virginia (Clayton) and southward.—Spikelets much smaller and more numerous than in the others.
6. S. mìnor, Vasey. Culms tufted, very slender, geniculate and ascending, simple, 1° high; leaves short and narrow; peduncles little exserted from the sheaths; spikelets (1½–2´´ long) in a very narrow simple compressed panicle (1–2´ long), not crowded; glumes and palet nearly equal, acute or somewhat acuminate.—Va. to N. C., Tenn. and Tex.
S. Índicus, R. Br. Culms stout, erect, 2–3° high; leaves elongated, attenuate; panicle very narrow, 6–18´ long, the densely crowded spikelets ½´´ long.—On ballast, and naturalized southward. (From Trop. Am.)
[*][*] Panicle pyramidal, open; glumes very unequal; grain globose, utricular; perennials.
7. S. júnceus, Kunth. Leaves involute, narrow, rigid, the lowest elongated; culm (1–2° high) naked above, bearing a narrow loose panicle; empty glumes ovate, rather obtuse, the lower one half as long as, the upper equalling, the nearly equal flowering glume and palet.—Dry soil, Penn. to Wisc. and Minn., and (chiefly) south to Fla. Aug.—Spikelets 1–2´´ long, shining.