Erect or nearly so, to 10 dm; basal lvs and lower stem-lf similar, long- petioled, the blade firm, broadly cordate to lanceolate, to 18 cm; spathe loosely sheathing, 3-6 cm; infl crowded, 5-15 cm; perianth funnelform, villous or shortly glandular-pubescent in bud, later often glabrate, violet-blue, rarely varying to white, the tube 5-7 mm, the lobes 7-10 mm; filaments pubescent; fr 5-10 mm, longer to sometimes shorter than wide; 2n=16. Marshes and shallow water; N.S. to Ont. and Minn., s. to S. Amer. (P. lanceolata)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.