Plants with well‑developed, scaly rhizomes, forming
tufts or small clumps. Flowering stems 30–100 cm long, erect or ascending
(sometimes spreading later in the season), glabrous and shiny between the nodes,
but roughened to minutely hairy just below the nodes. Leaf sheaths glabrous,
rounded or slightly angled on the back, the ligule 0.5–1.5 mm long. Leaf blades
3–5(–8) cm long, 1.5–4.0 mm wide, flat, relatively stiff, glabrous.
Inflorescences dense, spikelike, terminal and lateral panicles 2–5 cm long,
linear in outline, the base (especially in the usually abundant lateral
inflorescences) often enclosed by the subtending leaf sheath, the branches
short, appressed to the main axis. Spikelets 2–3 mm long, short‑stalked,
the stalks shorter than the spikelets. Glumes about the same length, 2–3 mm
long, about as long as the floret, lanceolate, only slightly overlapping at the
base, the margins relatively straight and tapered gradually to the sharply
pointed tip, strongly 1‑nerved, awnless or with an awn 0.2–0.5 mm long.
Lemma 2–3 mm long, lanceolate, the tip sharply pointed, awnless, glabrous
(including the base). Anthers 0.3–0.5 mm long. Fruits 1.0–1.5 mm long. 2n=40.
August–October.
Scattered mostly in central Missouri (Virginia to Iowa south to North Carolina, Alabama, and Texas). Bottomland forests, mesic upland
forests, bottomland and upland prairies, and margins of glades; also railroads.
This uncommon species is most frequently encountered in
clayey soils of moist to wet bottomlands. The name is sometimes spelled “glabriflora”
in floristic manuals, but Scribner’s original spelling of M. glabrifloris
should be preserved.