Plants bronze to dark brown when dry. Spathes: outer 30-56.7 mm, 12-25 mm longer than inner, connate basally 4-5.7 mm; inner with hyaline margins ending 0.9-1.9 mm proximal to green apex. 2n = 96.

Flowering late spring--early summer. Moist, rocky crevices, moist meadows especially near coast and along Saint Lawrence Seaway; 0--200 m; St. Pierre and Miquelon; N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que.; Conn., Maine, Mass., N.H., N.Y., R.I., Vt.