Dicksoniaceae

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GENERA (6) include Cibotium, Culcita, Dicksonia, Thysopteris, Cystodium, and Calochlaena.

THE DICKSONIACEAE are tropical ferns, and mostly Old World genera.

SORI are marginal, with a slightly elevated receptacle.

SPORANGIA are characterized by an annulus which is slightly oblique, and interrupted by the stalk.

SPORES are homosporous, and lack chlorophyll. They are consistently trilete, but otherwise diverse in structure.

STEMS range from erect (sometimes a single arborescent trunk) to decumbent or creeping. They may be stout to massive, but are usually unbranched and indurated. Stems are densely covered with long trichomes.

PETIOLES lack stipules.

LEAVES are usually large, ca. 1-3 m long, and pinnate. Circinate in bud, they may be glabrous to pubescent.

THE VASCULAR CYLINDER may be siphonostelic or dictyostelic.

THE GAMETOPHYTE is epigeal, and photosynthetic. Obcordate or cordate-elongate, it is somewhat thickened centrally. Archegonia and antheridia are both borne on the lower surface.


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