Plants erect. Leaves mostly cauline; blades to 22 cm long, 1.5-7 mm wide, lax to straight, conspicuously hirsute, usually with long stiff hairs and short soft hairs, grayish-green, margins hirsute. Panicle branches 2-11.2 cm; branch axes 0.3-0.9 mm wide. Spikelets 1.4-1.9 mm long, 1.1-1.6 mm wide, elliptic, obovate, orbicular, or suborbicular, pubescent to nearly glabrous; lower lemmas without an evident midvein; upper lemmas 1.3-2 mm.

Paspalum setaceum var. setaceum grows in open areas and sandy soils, often at the edges of forests, primarily on the southeastern coastal plain of the United States, from southern New England to eastern Mexico, but extending inland to western Virginia, Missouri, and Arkansas. It also grows in Cuba.

Perennial herb with short rhizomes or forming tufts 25 cm - 1 m tall

Leaves: mostly consisting of stem leaves, alternate, two-ranked. Sheaths open, sometimes hairy. Ligules to 0.5 mm long, membranous. Blades grayish green, straight to lax, to 22 cm long, 1.5 - 7 mm wide, lance-shaped, flat, parallel-veined, hairy, with short soft hairs and long stiff hairs.

Inflorescence: a branched arrangement of spikelets (panicle), terminal and axillary, bearing one to six spike-like branches. Axillary panicles completely or partially enclosed by a subtending leaf sheath. Branches ascending to spreading, often bowed, 2 - 11 cm long, with spikelets mostly arranged in two rows along one side of the branch. Branch axes 0.3 - 0.9 mm wide, sometimes rough.

Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea, white, elliptic to nearly orbicular.

Culm: upright, 25 cm - 1 m long, round in cross-section, hollow. Nodes sometimes hairy.

Spikelets: paired, overlapping, arranged along one side of the inflorescence branch, appressed to the branch axis, bearing two florets, straw-colored or brown, 1.5 - 2 mm long, 1 - 1.5 mm wide, plano-convex (one side flat, the other convex), nearly orbicular to orbicular to reverse egg-shaped to elliptic, nearly hairless to hairy.

Glumes:: Lower glumes absent. Upper glumes nearly equal to lower lemmas, rounded at the apex, three-veined, sometimes shortly glandular-hairy, membranous.

Lemmas:: Lower lemmas nearly equal to upper glumes, rounded at the apex, three-veined, sometimes shortly glandular-hairy, membranous. Upper lemmas clasping the paleas, straw-colored to brown, convex, smooth to slightly wrinkled, with rolled-up margins on the upper surface.

Paleas:: Lower paleas rudimentary or absent. Upper paleas straw-colored to brown, smooth to slightly wrinkled.

Florets:: Lower florets sterile. Upper florets bisexual, straw-colored, 1.5 - 2 mm long. Anthers three. Stigmas red.

Similar species: No information at this time.

Flowering: June to September

Habitat and ecology: Open areas and sandy soils.

Occurence in the Chicago region: native

Etymology: Paspalum comes from the Greek word paspalos, a type of millet. Setaceum means bristle-like.

Author: The Morton Arboretum