Asplenium rhizophyllum L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Rhizome ca 2 mm thick, the scales lance-subulate, entire, dark brown, iridescent; petiole flattened, winged, green except at the dark brown scaly base; blade simple, 5–30 cm, undulate-margined, generally cordate at base with rounded auricles, to 3 cm wide at base, tapering gradually to a flagelliform rooting tip; veins anastomosing, the areoles mostly in 2 rows, the outer veinlets free; 2n=72. Mostly on rocks, esp. limestone; Que. and Ont. to Minn., s. to Ga. and Okla. (Camptosorus r.)