Flora of North America species comparison

creeping to suberect or ascending, sometimes climbing [rarely arborescent], slender to stout, dictyostelic, scaly.

monomorphic or dimorphic, large and coarse, generally greater than 30 cm, often exceeding 1 m. Petiole not articulate, generally more than 2 vascular bundles arranged in arc, generally scaly at least at base.

often anthocyanic (reddish) when young, pinnatifid [rarely simple] to pinnate-pinnatifid or 2-pinnate [rarely decompound], glabrous or occasionally bearing scales or capitate glands.

of sterile leaves generally free, rarely anastomosing, veins of fertile leaves united to form sorus-bearing secondary vein parallel to costa or costule (vascular commisure), sometimes anastomosing further.

elongate along secondary vein;

indusia present [rarely absent], opening along costal side of fertile vein, frequently hidden by dehisced sporangia;

sporangial stalk of 3 rows of cells.

monolete, reniform;

perine present, variously ornamented.

green, cordate, sometimes bearing capitate hairs, antheridia and archegonia borne on lower surface.

frequently grooved adaxially.