The World Flora Online

Plants perennial, mostly terrestrial, rarely epiphytic, generally in mesic, forested habitats. Stems short- to long-creeping, solenostelic [protostelic], bearing hairs (or less often scales), often branching by means of buds on proximal part of petiole. Leaves monomorphic, circinate in bud. Petiole not articulate, with 1--many vascular bundles, hairy or glabrous [scaly]. Blade 1-pinnate to decompound (rarely simple), glabrous or hairy or with mixture of hairs and glands; rachis and costae grooved adaxially [not grooved in some genera]. Veins free or sometimes joined at margin in fertile segments, pinnate or forking in ultimate segments. Sori near or at blade margin on vein tips or submarginal commissural vein; true (inner) indusia present, free or fused with portion of blade margin to form cup or pouch, or obscured by revolute and usually modified portion of blade margin [indusia rarely absent]; sporangial stalk of 1--3 rows of cells. Spores not green, tetrahedral or bilateral, monolete or trilete. Gametophytes green, cordate, with archegonia and antheridia borne on lower surface.

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Plants terrestrial, sometimes climbing. Rhizome usually long creeping, solenostelic, siphonostelic, or polystelic, usually covered with multicellular hairs, less often with few-celled, cylindrical, glandular hairs or multicellular bristles, scales absent. Fronds medium-sized to large, sometimes indeterminate, monomorphic; stipes not articulate to rhizome, usually hairy, rarely glabrous; lamina 1-4-pinnately compound, thinly herbaceous to leathery, hairy or glabrous, without scales; rachis grooved adaxially, sometimes with buds (Monachosorum); pinnae opposite or alternate; veins usually free, pinnate or forked, not reaching margin, reticulate without included veinlets in Histiopteris. Sori marginal or intramarginal, linear or orbicular, terminal on a veinlet or on a vascular commissure joining apices of veins; indusia linear or bowl-shaped, sometimes double with outer false indusium formed from thin reflexed lamina margin and inconspicuous inner true indusium; paraphyses present or not. Spores tetrahedral and trilete, or reniform and monolete, spinulose, tuberculate, or smooth. Gametophytes green, cordate. x = 26, 29, 30, 31, 33, 34, 38, 46, 47, 48, and probably others.

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Rhizomes creeping, hairy, vascular system solenostelic or in Pteridium a complex double solenostele; stipes with convoluted undivided vascular strands, which are sometimes U–shaped or with a system of several bundles in a horseshoe arrangement

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Rhizome rampant, portant des poils, solénostélique. Fronde de grande taille, pluripennée, portant souvent des aérophores ou des nectaires à la base des pennes. Nervures libres ou anastomosées. Costa canaliculé, le sillon des axes latéraux décurrent sur celui du rachis principal. Sores marginaux ou submarginaux, ponctiformes ou allongés. Indusie absente, ou en forme de coupe, ou linéaire, marge recourbée de la feuille formant parfois une fausse indusie. Sporange courtement pédicellé, ne naissant pas tout à fait tous en même temps (position intermédiaire), souvent mélangés de paraphyses.

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SELECTED REFERENCES

Holttum, R. E. 1947. A revised classification of the leptosporangiate ferns. J. Linn. Soc., Bot. 51: 123--158. Mickel, J. T. 1973. Position of and classification within the Dennstaedtiaceae. In: A. C. Jermy et al., eds. 1973. The Phylogeny and Classification of the Ferns. London. Pp. 135--144. [Bot. J. Linn. Soc., Suppl. 1.]

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