Narrow triangle moonwort

Botrychium lanceolatum var. angustisegmentum Pease & A.H. Moore, Rhodora 8: 229. 1906; B. angustisegmentum (Pease & A.H. Moore) Fernald

Plants slender. Leaf base , including sheath, to 0.7cm diam., usually swollen only 1--3 times width of common stalk (dried). Common stalk dark brownish green, trophophore blade dark green, very shiny. Segments narrow, ultimate lobes narrowly linear-oblong, 1--2 mm wide, blade tissue thin but firm. Pinnae and lobes mostly sharply pointed. Sporangia 0.7--1 mm diam., slightly immersed, mostly ± separated and exposing sporangiophore midrib.

Leaves appearing in late spring or early summer, releasing spores later than most associated species, and dying as late as October. Mainly in shaded woods; 0--1200m; St. Pierre and Miquelon; Alta., B.C., N.B., Nfld., N.S., Ont., Que., Sask., Yukon; Conn., Ky., Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.