A revision of the genus Riccia (Hepaticae) in Australia.

Abstract

Spore features are the least variable characters and therefore the most reliable for taxonomic purposes. A key for the identification of the 33 species is provided. All species are described and illustrated with line drawings, chromosome numbers are reported, typification and relationships are discussed, and collections are listed; scanning electron micrographs of the spores are provided for 29 species. New taxa described include one section (Viridisquamata), nine species (R. areolata, R. blackii, R. caroliniana, R. collata, R. luticola, R. longiciliata, R. olgensis, R. rorida and R. spongiosula), and five varieties (R. duplex var. megaspora, R. rnultifida var. divaricata, R. rnj?da var. jiliformis, R. mult~jida var. torticolla and R. papulosa var. variabilis). Two binomials are considered to be of uncertain status.