Pecluma, a New Tropical American Fern Genus

Abstract

The species of Pecluma were submerged in Polypodium until moder taxonomists separated Grammitids from Polypods. Then, Copeland (1956) included some members of Pecluma in a generic treatment of the Grammitid Ctenopteris. That provided the impetus for three papers which supplied evidence that Pecluma species indeed belonged with Polypodium (Stokey, 1959; Wilson, 1959; Sota, 1963). A later revision of the individual species by Evans (1969) has facilitated a new examination of the relationships of the group, and I have come to the conclusion that those authors who reaffirmed an alliance with Polypodium are correct, but that Copeland's error may be partly excused on the grounds that Pecluma also has many features reflecting a shared ancestry with Ctenopteris, features that mark it as abundantly distinct from Polypodium. The most conspicuous of these differences from Polypodium are: rhizomes short and non-branching, paleae basally attached, axes terete, and fronds pectinate. From Ctenopteris, diagnostic differences are: spores neither trilete nor green, hairs never acicular from a broad base and not dark maroon, and stipes articulate. These and other characters are detailed below.