2. Leptochloa fusca (L.) Kunth

Pl. 150 a, b; Map 608

Plants annual, forming tufts or small clumps. Flowering stems 15–120 cm long, erect to spreading, often ascending from spreading bases. Leaf sheaths rounded on the back or keeled, glabrous or somewhat roughened, the ligule 0.5–6.0 mm long, usually irregularly divided along the margin. Leaf blades 3–45 cm long, 2–7 mm wide, glabrous or slightly roughened. Inflorescences 5–50 cm long, with 8–35 branches, these 3–25 cm long. Spikelets 5–12 mm long, moderately flattened, with 6–12 florets. Lower glume 1–3 mm long, lanceolate, sharply pointed at the tip. Upper glume 1.8–5.0 mm long, elliptic‑ovate to obovate, sharply pointed at the tip. Lemmas 2.3–5.0 mm long, narrowly lanceolate to ovate, sharply pointed to rounded or truncate at the tip, sometimes minutely notched or with 2 minute teeth, awnless or more commonly with an awn 0.5–2.5 mm long, keeled. Anthers 0.2–1.0 mm long. Fruits 1–2 mm long, elliptic to obovate in outline, slightly flattened. 2n=20. July–October.

Scattered, most commonly in counties adjacent to the Missouri and Mississippi Rivers (U.S. and adjacent Canada, Mexico, Central America, South America, Caribbean Islands). Banks of streams and rivers, margins of ponds and lakes, saline marshes and seeps, openings of bottomland forests, and rarely moist depressions of glades; also roadsides, railroads, ditches, and open, disturbed areas.

The name L. fusca is used here in anticipation of its conservation over the older but relatively obscure and somewhat controversial epithet L. malabarica L. As treated by Snow (1997, 1998), the species consists of four subspecies, two of which are widespread in the New World and two that occur in the Old World.