The World Flora Online

Plants perennial [annual], on rock or terrestrial, of small (rarely large) stature . Stems compact to creeping, branched or unbranched, dictyostelic, bearing hairs and/or scales. Leaves monomorphic to dimorphic, circinate or noncircinate in bud . Petioles usually with persistent scales proximally, lacking spines; vascular bundles 1--several, roundish or crescent-shaped in cross section. Blades 1--6-pinnate, without laminar buds . Indument on petioles, rachises, costae, and blades, rarely absent or commonly of hairs, glands, and/or scales, occasionally of white or yellow farina. Veins pinnate or parallel in ultimate segments of blades, simple or forked, free or infrequently anastomosing in complex patterns. Sori borne abaxially on veins, often confluent with age and forming a continuous submarginal band, or sporangia densely covering abaxial surface (acrostichoid); receptacle not or only slightly elevated. Indusia (when present) formed by reflexed, recurved, or revolute leaf margin (false indusium). Sporangia stalk of 2--3 rows of cells; annulus vertical, interrupted by stalk; spores 64 or 32 (rarely 16) per sporangium. Spores all 1 kind, brown, black, or gray (rarely yellow), globose to globose-tetrahedral or trigonal, occasionally with prominent equatorial ridge, trilete, or trigonal, variously ornamented (usually cristate or rugose). Gametophytes green, aboveground, obcordate to reniform, sometimes asymmetric, usually glabrous (glandular-farinose in Notholaena ); archegonia and antheridia borne on abaxial surface, antheridia 3-celled.

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Plants mostly terrestrial or epilithic, some epiphytic, rarely aquatic (Ceratopteris), small to large. Rhizomes erect, ascending, or creeping, siphonostelic, solenostelic, or dictyostelic, usually scaly, rarely with bristles; scales brown or black, sometimes clathrate and iridescent, lanceolate to cordate, sometimes peltate, margin usually entire. Fronds mostly monomorphic, less often dimorphic or subdimorphic, clustered to widely scattered, not articulate; stipe well defined, dark, often glossy, to ill defined and green, terete or adaxially grooved, glabrous, hairy, or scaly, with 1-4 vascular bundles (or to many in Ceratopteris) near base, combining distally; lamina entire or 1-4-pinnate to 5-pinnate-pinnatifid, less often digitate, pedate, or 1-3 dichotomous with pedate branches; ultimate pinnules often stalked, sometimes articulate, herbaceous, papery, or leathery, more rarely membranous or fleshy; veins free or anastomosing, if anastomosing then areoles without free included veinlets. Sori mostly confluent along veins or marginal commissures, sometimes immersed in grooves, less often discrete on vein tips or on recurved membranous marginal lobe (false indusium), sometimes acrostichoid or rarely forming a narrow longitudinal band between midrib and margin (Taenitis); true indusium absent, marginal sori often protected by false indusium formed from revolute lamina margin. Sporangia usually long stalked, annulus vertical or rarely oblique, interrupted by stalk. Spores mostly brown, yellowish, or colorless, mostly tetrahedral-globose and trilete, rarely ellipsoid and monolete, smooth or ornamented, sometimes with an equatorial flange. Mostly x = 29, 30.

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Terrestrial (including saline and freshwater swamp dwellers) or growing on rocks; rhizome erect or creeping, solenostelic or dictyostelic with basifixed ± entire mostly non-clathrate scales

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As constituted here the family contains 5 genera spread throughout the tropics and warm temperate areas. Tryon and Kramer in Kubitzki, Fam. Gen. Fl. Pl. 1: 230 (1990) maintain Pteridaceae as a much larger unit with 6 subfamilies and 34 genera. See also Pichi Sermolli in Webbia 31: 393–395 (1972)

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SELECTED REFERENCES

Lellinger, D. B. 1985. A Field Manual of the Ferns & Fern-allies of the United States & Canada. Washington. Mickel, J. T. 1979b. The fern genus Cheilanthes in the continental United States. Phytologia 41: 431--437. Pichi-Sermolli, R. E. G. 1977. Tentamen pteridophytorum genera in taxonomicum ordinem redigendi. Webbia 31: 313--512. Tryon, R. M. and A. F. Tryon. 1982. Ferns and Allied Plants, with Special Reference to Tropical America. New York, Heidelberg, and Berlin.

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