Bulbs mostly 4-6 × 1.5-3 cm. Leaf blade (3-)5-9 cm wide, evidently petiolate, sheaths and petioles commonly anthocyanous. Scape (12-)25-35 cm. Umbel (15-)30-50-flowered; spathe bracts 2-3 cm. 2n = 16. Flowering Jul--Aug. Moist ground in rich woods, depressions, streamside bluffs, and colluvial slopes; 0--1400 m; N.B., N.S., Ont., Que.; Ala., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis.