Mem. Torrey Bot. Club 5: 110. 1894.
Bulbs slender, ellipsoid, 3–8 cm. Stems 5–20 dm. Leaves numerous, ascending; blade narrowly linear, channeled, 20–70 × 0.5–3 cm, apex acuminate to obtuse. Inflorescences freely branching, terminal panicles of many compound racemes; terminal racemes longer than lateral; bracts linear, 2 mm. Flowers erect; perianth rotate; tepals not recurved distally, white to greenish yellow, narrowly lanceolate, 4–10 × 1–2 mm, apex acute to narrowly acuminate; tepal glands absent; stamens 1–4 mm; filaments equal; pedicel divergent, 4–6 mm. Capsules oblong, cylindric to ovoid, 6–10 mm including divergent style beaks. Seeds brown, ellipsoid to lanceoloid, 5–8(–10) mm. 2n = 20.
Phenology: Flowering mid–late summer.
Habitat: Moist woods, thickets, and meadows
Elevation: 0–1200 m
Ala., Ark., D.C., Fla., Ga., Ill., Ind., Ky., La., Md., Mich., Mo., N.C., Ohio, Pa., S.C., Tenn., Tex., Va., W.Va.
Stenanthium gramineum shares molecular affinities with the Zigadenus densus (Desrousseaux) Fernald and Z. leimanthoides A. Gray species pair (W. B. Zomlefer et al. 2001).
The varieties of Stenanthium gramineum recognized by M. L. Fernald, but not here, are indistinct and sympatric (R. R. Gates 1918; R. G. Johnson 1969). The disjunct upper Michigan localities represent locally established waifs (E. G. Voss 1972–1985, vol. 1).