11. Panicum flexile (Gatt.) Scribn. (wiry witchgrass, slender panic grass)

Pl. 170 d; Map 672

Plants annual, forming tufts. Flowering stems 10–70 cm long, relatively slender, more or less circular in cross‑section, glabrous or hairy. Leaves scattered along the stems. Leaf sheaths rounded on the back, hairy, the hairs without pustular bases (rarely pustular‑based elsewhere), the ligule 0.3–1.0 mm long, a line or band of hairs (usually with a minute membrane at the base). Leaf blades 2–30 cm long, 2–7 mm wide, relatively soft, erect or ascending, glabrous or sparsely hairy, flat. Inflorescences 5–30 cm long, usually more than 1/2 as long as the entire flowering stem, 2–3 times as long as wide, remaining attached to the flowering stem at maturity, not becoming a “tumbleweed,” the primary branches ascending to spreading, not spikelike, rebranched several times, the spikelets not appearing 1‑sided, mostly single at the branch tips, mostly long‑stalked, not curved or angled with respect to their stalks. Spikelets 2.5–3.6 mm long, elliptic in outline, tapered to a relatively long, narrow, sharp point at the tip, glabrous. Lower glume 1.0–1.7 mm long, 1/3–1/2 as long as the rest of the spikelet, ovate, sharply pointed at the tip, 3‑ or 5‑nerved. Upper glume 2.4–3.4 mm long, elliptic, tapered to a relatively long, narrow, sharp point at the tip, 7‑ or 9‑nerved. Lowermost floret sterile and without a palea, the lemma 2.4–3.4 mm long, elliptic, 7‑ or 9‑nerved. Fertile floret 1.7–2.2 mm long, elliptic, bluntly pointed at the tip. Anthers 1.0–1.4 mm long. Fruits 1.2–2.0 mm long, narrowly elliptic to elliptic in outline, light yellow or straw‑colored at maturity. 2n=18. July–October.

Scattered to common nearly throughout the state, most common south of the Missouri River (eastern U.S. and adjacent Canada west to North Dakota and Texas). Glades and ledges of bluffs (on both calcareous and acidic substrates), upland prairies, openings of mesic to dry upland forests, fens, and gravel bars and banks of streams; also roadsides and open, disturbed areas.