Morphology and Anatomy of the Genera Davallia, Araiostegia and Davallodes, with a Discussion on Their Affinities

Anatomical and morphological details are recorded for the species Davallia denticulata (Burm. f.) Mett., D. solida (Forst.) Sw., Humata repens (L. f.) Diels, Araiostegia membranulosa (Wall. ex Hook.) Holtt., A. multidentata (Wall. ex Hook.) Copel. and Davallodes borneense (Hook.) Copel. The distinctive characters of the genera are discussed, based on the details described and also on a consideration of other species. A new assessment is made of the distinctions between Araiostegia and Davallodes; this involves consideration of Paradavallodes Ching, a genus established to include Araiostegia membranulosa and A. multidentata. It is concluded that the species included by Ching in Paradavallodes are not sufficiently distinct from those left by him in Araiostegia to warrant recognition of the new genus. The species originally named Davallia membranulosa Wall. ex Hook., placed by Copeland in Davallodes and by Ching in Paradavallodes, is therefore here transferred to Araiostegia. The concluding discussion includes reference to the status and contents of the family Davalliaceae and its possible relationships to other families; it is suggested that (as here delimited) it is an epiphytically adapted offshoot from the terrestrial group of ferns which includes Tectaria.