Rhizome ±creeping; lvs scattered, 6-11 dm, the blade longer than the petiole, 11-20 cm wide, gradually tapering above, only slightly reduced below, glabrous except for a few septate brown hairs on the rachis, costae, and veins; pinnae 20-30 pairs, subdimorphic, the fertile one slightly narrower than the sterile; sterile pinnae narrowly lance- linear, 7-12 cm נ10-13 mm, subsessile and rounded or subtruncate at the base, gradually tapering to the base, subentire or slightly toothed, the veins simple or forked, tending to run to the sinuses; indusia glabrous, narrow, elongate, straight or nearly so, following the anterior vein-branch and often reaching from near the costa to near the margin; 2n=80. Cool woods and talus slopes in circumneutral soil; s. Que. to Ont. and Minn., s. to Fla. and La. (Asplenium p.; Diplazium p.; Homalosorus p.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.