Evolution and speciation inPellia, with special reference to thePellia megaspora-endiviifoliacomplex (Metzgeriales), I. Taxonomy and distribution

Abstract

The genus Pellia, with 3 currently recognized species, includes a relatively primitive taxon, P. endiviifolia, in which the perichaetium is high and incised, with an enclosed calyptra. It is dioecious, produces anthocyanin wall pigments in exposed sites, reproduces asexually by repeatedly furcate, narrow fragmenting autumnal innovations, is freely branched and has small spores. A species previously confused with this taxon and here described as P. megaspora, is an endemic boreal American species, found from New York, Connecticut and Massachusetts [USA] north to Newfoundland [Canada] and west to Minnesota [USA]. The plant has a tall perichaetium that is strikingly incised.sbd.ciliate to lacerate. It is dioecious but does not produce wall pigments and autumnal innovations, is simple or once-furcate and has large spores. Cytological and biochemical data support the specific recognition of P. megaspora. Biochemical data also suggest that Japanese populations currently assigned to P. endiviifolia are distinct and field observation suggests that these plants may represent an autonomous subspecies.