Weston Testo
American Fern Journal 108 (1), 27-33, (27 March 2018) https://doi.org/10.1640/0002-8444-108.1.27
KEYWORDS: Central America, Neotropics, new species, Pityrogramma, taxonomy
Pityrogramma hirsuta Testo is described from a secondary lowland rain forest on the Osa Peninsula of Costa Rica. It is distinguished from all other Costa Rican Pityrogramma species by a combination of once-pinnate-pinnatifid laminae, abundant whitish hairs on the petiole, rachis, and laminar surface, and complete lack of farina on the abaxial laminar surface. A hybrid between this species and Pityrogramma calomelanos (L.) Link, Pityrogramma ×watkinsii Testo is also described. It is morphologically intermediate to its progenitors and is characterized by an indument of whitish hairs on the petiole, rachis, and laminar surface, and sparse white farina on the abaxial surface of the lamina. The new species and hybrid are each known only from the type collections. Relationships to other species of Pityrogramma are discussed, and a key to Central American Pityrogramma is presented.