Athyrium filix-femina (L.) Roth
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Rhizome short-creeping to suberect, the lvs clustered near its tip, 4–10 dm; blade 10–35 cm wide, acuminate, slightly reduced below, sparsely scaly, otherwise glabrous or minutely glandular, mostly bipinnate or bipinnate-pinnatifid; pinnae 20–30 pairs below the pinnatifid tip, lance-linear, subsessile, attenuate-acuminate, the pinnules mostly serrate to deeply parted, obtuse to acuminate; veins forking, directed into the teeth; indusia dark brown, thin, ciliate (at least when young) mostly short and ± curved or hooked, commonly crossing the veins; 2n=80. Moist woods, meadows, and streambanks; cosmopolitan and highly variable, two vars.