Pityrogramma opalescens (Pteridaceae), a New Species from Cerro del Torra, Colombia

A new species, Pityrogramma opalescens, is described; it is known only from Cerro del Terra, an isolated mountain peak in the Cordillera Occidental of Colombia, which is a region of high diversity and endemism. It is most similar to Pityrogramma lehmannii, and the two species differ from all other Pityrogramma species by having creeping rhizomes, rhizome scales with turgid cells, an elongate, proximally 1-pinnate lamina, with sessile segments supplied by multiple veins that emerge from the rachis rather than from a single main vein, and farina on the abaxial side of the lamina that is borne at the apex of short hairs. It differs from P. lehmannii by more numerous segments that are narrower (3.5-4.0 mm wide vs. 10.0-17.0 mm wide), with more acutely rounded apices, and dull-yellow rather than white farina abaxially.