Stems 0.5-2 m, nearly glabrous to densely tomentose. Leaves ovate to elliptic, reduced distally, to lanceolate, 15-35 × 8-20 cm, glabrous to densely hairy, especially on abaxial surface. Inflorescences paniculate, with ascending to spreading or distinctly drooping (particularly in w North America) branches, 30-70 cm, tomentose; bracts lanceolate, shorter than flowers. Tepals deep green to yellowish, lanceolate to oblong-elliptic, narrowed to short, broad claw, 5-12 mm, tomentose adaxially, margins of both whorls or at least inner obviously erose-serrulate; gland 1, basal, dark green or yellowish green, V-shaped; ovary glabrous; pedicel 2-10 mm. Capsules oblong-ovoid, 2-3 cm, glabrous. Seeds flat, broadly winged, 8-10 mm. Veratrum viride consists of two clearly related, disjunct populations, one in eastern and one in western North America. These were clearly separated by continental glaciation and have subsequently evolved in isolation. Nonetheless they show many critical features in common, and individual plants from either region occasionally show one or more features common to plants in the other. The two populations have been variously classified as separate species, varieties, or subspecies, or as a single taxon. We have chosen to recognize two distinctive, if subtle, varieties.
Stem stout, erect, leafy to the top, to 2 m; lvs sessile or nearly so, often somewhat clasping, plicate, oval or elliptic, to 3 dm, half as wide; panicle freely branched, 2-5 dm, hairy; pedicels 2-4 mm; tep yellowish-green, elliptic or broadly lanceolate, 8-13 mm, narrowed to the base, ciliate; filaments erect, shorter than and free from the perianth; fr ovoid, 18-25 mm; 2n=32. Swamps and wet woods; Que. to Ont., s. to N.C.; Alas. to Oreg. June, July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.