Pityrogramma Link

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Small to medium-sized terrestrial or epipetric ferns

Vegetative Multiplication Rhizomes

Rhizomes short-creeping to erect, clothed with narrow, more or less attenuate, non-clathrate scales

Morphology Leaves

Blades 1–3- pinnate, narrowly oblong or lanceolate to ovate or deltate, usually covered on abaxial side with white or yellow to nearly orange wax-like powder, otherwise naked or rarely with scales; veins free, pinnately forked Fronds fasciculate, all similar or sub-dimorphic, not articulate to the rhizome; stipes usually dark, hard, and lustrous

Morphology Reproductive morphology Sori

Sori indefinite and 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.

Distribution

A small genus of fewer than 20 species, most of them occurring in the neotropical region.

Etymology

The generic name is derived from the Greek pityron, meaning scurf or farina, and gramme, meaning line;

Recognition

The undersurface of the fronds is covered with farina-like powder, and the sporangia are in lines along the veins.