Plants perennial, mostly terrestrial, occasionally on rock or epiphytic. Stems creeping to suberect or ascending, sometimes climbing [rarely arborescent], slender to stout, dictyostelic, scaly. Leaves 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. Blade often anthocyanic (reddish) when young, pinnatifid [rarely simple] to pinnate-pinnatifid or 2-pinnate [rarely decompound], glabrous or occasionally bearing scales or capitate glands. Rachis frequently grooved adaxially. Veins 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. Sori 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. Spores monolete, reniform; perine present, variously ornamented. Gametophytes green, cordate, sometimes bearing capitate hairs, antheridia and archegonia borne on lower surface.
Plants mostly terrestrial, sometimes tree ferns (like small trees), rarely scandent. Rhizome mostly erect, or creeping or scandent, usually dictyostelic (Stenochlaena meristelic), scales brown, entire. Fronds monomorphic or dimorphic, mostly long stipitate; stipe with 2 to several vascular bundles, scaly at base; lamina pinnate, pinnatifid, or bipinnatifid, rarely simple, thickly papery to leathery, glabrous or usually with small scales; pinnae rarely articulate to rachis (Stenochlaena); veins free or anastomosing with 1 or more series of areoles, without included free veinlets. Sori elongate or continuous along vascular network or commissure on either side of midrib, indusiate, rarely exindusiate, rarely acrostichoid; indusium facing toward costa or costule; annulus longitudinal, interrupted. Spores elliptic, bilateral, monolete.
Rhizome forming an erect trunk or wide–climbing, scaly at apex
Rhizomes erect to long-creeping, scaly, scales not clathrate
This indusium is really a false indusium or modified leaf margin and the photosynthetic lamina of the fertile frond of Eu–Blechnum, which forms a flange extending beyond the indusium is a new structure (see Bower Ferns 3: 165 (1928))
|Chain Fern Family|