Plants erect to spreading. Leaves mostly cauline;
blades to 30 cm long, 3.3-13.5 mm wide, lax to somewhat stiff, glabrous
or with a few hairs along the midrib, sometimes pubescent, yellow-green to dark
green, margins scabrous, ciliate. Panicle branches 4-12 cm; branch
axes 0.6-1.1 mm wide. Spikelets 1.7-2.4 mm long, 1.5-2.1 mm wide,
obovate to suborbicular, pubescent or occasionally glabrous; lower lemmas
without an evident midvein; upper florets 1.7-2.1 mm.
Paspalum setaceum var. stramineum grows at the edges of forests
and in disturbed areas with sandy soil. Its range extends from the central plains
and eastern United States to Mexico, Bermuda, and the West Indies.
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 more or less stiff to lax, to 30 cm long, 3.5 - 13.5 mm wide, lance-shaped, flat, parallel-veined, sometimes with a few hairs along the midrib, rough along the margins, fringed with 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, 4 - 12 cm long, with spikelets mostly arranged in two rows along one side of the branch. Branch axes 0.5 - 1 mm wide, sometimes rough. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea, white, elliptic to nearly orbicular. Culm: upright or spreading, 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 - 2.5 mm long, 1.5 - 2 mm wide, plano-convex (one side flat, the other convex), nearly orbicular to reverse egg-shaped, hairy or occasionally hairless. 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: Sandy prairies and disturbed sandy areas.
Occurence in the Chicago region: native
Etymology: Paspalum comes from the Greek word paspalos, a type of millet. Setaceum means bristle-like. Stramineum means straw-colored.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
A few specimens of this species have been found in a few of the northwestern counties in very dry, sandy soil along roadsides and in waste places.