2. Sphenopholis obtusata (Michx.) Scribn. (prairie wedgescale, wedgegrass)

Pl. 136 a, b, i, j; Map 551

Plants annual or perennial, forming tufts. Flowering stems 20–120 cm long. Leaf sheaths hairy or the uppermost glabrous or roughened, the ligule 1–3 mm long. Leaf blades 2–20 cm long, 2–8 mm wide, hairy or the uppermost ones sometimes only roughened. Inflorescences 4–20 cm long, relatively narrow to open, erect to more commonly arched or somewhat drooping, the branches ascending or spreading. Spikelets 1.5–5.0 mm long. Lower glume 1.0–3.2 mm long, 0.1–0.3 mm wide in side view, less than 1/3 as wide as the other glume, linear, 1(3)‑nerved. Upper glume 1.2–4.5 mm long, oblanceolate to obovate, rounded to bluntly pointed at the tip. Lemmas 1.4–4.5 mm long (shorter in the uppermost floret of 3‑flowered spikelets), oblong‑elliptic, bluntly to sharply pointed at the tip, both smooth to slightly or minutely roughened and awnless. Anthers 0.3–0.8 mm long. Fruits 1.4–2.0 mm long. 2n=14. April–July.

Scattered to common throughout the state (U.S., Canada, Alaska, Mexico, Caribbean Islands). Bottomland forests, mesic to dry upland forests, upland prairies, glades, ledges and tops of bluffs, banks of spring branches, streams, and rivers, and margins of ponds and sinkhole ponds; also roadsides, railroads, old fields, pastures, and disturbed, open areas.

The two varieties of S. obtusata have often been treated as separate species (Steyermark, 1963), but Erdman (1965) documented a number of fertile intermediates between them.