Rhizomes 0.5-2 × 0.5-1.8 cm; bulbs 0.6-2.5 cm. Stems 1/4-1/3 floriferous, 0.6-2 m. Leaf blades linear, long-attenuate, 30-80 × 0.6-3.2 cm, apex acute. Inflorescences 1.3-8 dm; terminal raceme 1-2.6 dm; secondary racemes spreading to ascending, 0.2-1.1(-2.2) dm; tertiary racemes infrequent; bracts obovate to subulate, green to brown, 2-4(-6) mm, densely floccose abaxially and marginally. Tepals greenish yellow, aging dark reddish purple, ovate to obovate-oblong, 5.5-13 × 2.2-6 mm, base abruptly auriculate to hastate, clawed, margins entire, apex acute, claws 0.5-1.2(-2.5) mm; glands yellowish green, oblong to oblong-ovate, nectariferous; stamens 6.5-8.5 mm; filaments inserted at or above middle of claw, 0.7-2.5 mm from ovary base, not basally dilated, equaling tepal width at insertion point; anthers 0.9 mm; ovary ovoid, glabrous or pubescent; styles 1.5-3.5 mm; pedicel spreading to ascending, 5-20 mm. Capsules elliptic-ovoid, 10-18 × 6-10 mm, glabrous or glabrate. Seeds 5-8 × 2.5-4 mm (including wings). 2n = 16. Flowering late spring--summer. Bogs, marshes, wet woods, savannas, meadows, along railroads; 10--800 m; Ala., Ark., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Miss., Mo., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va. The clawed tepals of Melanthium virginicum distinguish it from M. parviflorum and M. woodii, which have tepals with gradually attenuate bases.