The World Flora Online

Plants perennial, terrestrial or on rock, occasionally hemiepiphytic or epiphytic. Stems creeping to erect, rarely arborescent, sometimes climbing, branched or unbranched, dictyostelic, bearing scales. Leaves circinate in bud, monomorphic or dimorphic. Petiole usually not articulate to stem, scales usually persistent at base, in cross section with 2--many roundish bundles, or bundles 2 and lunate. Blade simple to commonly 1--5-pinnate or more divided, leaf buds absent or present. Veins pinnate or parallel in ultimate segments, simple or forked, free or anastomosing, areoles sometimes with included free veinlets. Indument on blade commonly of glands, hairs, and/or scales, especially on rachis and costae abaxially. Sori borne abaxially on veins or at vein tips (but usually not marginal), or sporangia acrostichoid and covering abaxial surface, if in discrete sori then variously shaped (round, oblong, or elongate); receptacle not or only slightly elevated, with or without indusium, indusium variously linear, falcate, or reniform, sometimes hoodlike, cuplike, or round. Sporangia with stalk of 2--3 rows of cells; annulus vertical, interrupted by stalk. Spores all of 1 kind, usually not green (except Matteuccia , Onoclea ), oblong or reniform in outline, monolete, variously ornamented (often broadly winged), 64 per sporangium (32 in apogamous spp.). Gametophytes green, aboveground, cordate, glabrous or often bearing glands or hairs; archegonia and antheridia borne on lower surface, antheridia 3-celled.

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Plants small to large, evergreen or deciduous, terrestrial, epilithic, hemiepiphytic, or epiphytic. Rhizomes erect, ascending, creeping, or sometimes climbing, dictyostelic (mostly radially), scaly; scales basally attached or very rarely peltate, often non-clathrate but sometimes clathrate, entire or dentate. Fronds caespitose or remote from one another, with segments anadromously or catadromously arranged, or sometimes anadromous at base and catadromous distally; stipe often not articulate but sometimes articulate at base, with 3 or more vascular bundles arranged in a semicircle or circle, scaly, sulcate adaxially, not hairy or sometimes hairy; lamina monomorphic or dimorphic, usually oblong, deltoid, pentagonal, lanceolate, ovate, or linear, 1-5-pinnate, or simple, rarely imparipinnate, scaly, glandular, hairy, or glabrous; if scaly then scales bullate or flat; glands absent or present; texture thinly papery, papery, or leathery. Rachises sulcate adaxially, with or without proliferous bulbils, rarely proliferous bulbils borne at a prolonged flagelliform rachis terminal; venation pinnate and free, or variously anastomosing to form 1 to multiple rows of areoles, with or without included veinlets. Fertile fronds conform or weakly to strongly difform with sterile fronds. Sporangia usually in orbicular sori; sori terminal, subterminal, or dorsal on veins, indusiate or rarely exindusiate; if indusiate then indusia orbicular or reniform or rarely ovoid, superior, lateral, or rarely inferior, sessile or rarely stalked, entire or toothed; sometimes sporangia nearly evenly covering fertile parts abaxially (not forming orbicular sori); sporangia with 3-rowed, short to long stalks. Spores monolete, achlorophyllous, with prominent perispore. x = 41.

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