Pityrogramma
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Authority
Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.
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Family
Pteridaceae
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Scientific Name
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Description
Genus Description - Small to medium-sized terrestrial or epilithic ferns. Rhizomes short-creeping to erect, clothed with narrow, more or less attenuate, nonclathrate scales. Fronds fasciculate, all similar or somewhat dimorphic, not articulate to the rhizome; stipes usually dark, hard, and lustrous; blades 1- to 3-pinnate, narrowly oblong or lanceolate to ovate or triangular, usually covered on lower surface with white or yellow to nearly orange waxlike powder, otherwise naked or rarely with scales; veins free, pinnately forked. Sori indefinite; indusium absent; sporangia produced along the course of the veins and often at maturity forming confluent lines or masses; annulus of 20-24 cells; spores tetrahedral-globose, trilete, the surface coarsely tuberculate, reticulate, or ridged, rarely smooth and minutely granulate.