Systematics of the Xanthosia pilosa complex (Apiaceae : Hydrocotyloideae)

Xanthosia pilosa Rudge is a common shrub found in eastern Australia. The sp ecies complex displays a wide range of variation in leaf and inflorescence morphology which has resulted in the application of numerous species names and its informal division into numerous variants in New South Wales. As par t of a revision of the genus, the history of the species complex is reviewe d and the morphology of the numerous variants, examined both in the field a nd herbarium, is discussed. Xanthosia pilosa sens. lat. is here divided int o four species: two new species (X. scopulicola J.M. Hart & Henwood and X. stellata J.M. Hart & Henwood) are described and illustrated, a substitute n ame (X. ternifolia J.M. Hart & Henwood) is provided for the illegitimate X. tasmanica Gand., and X. pilosa s.s., which remains a polymorphic species i n which further segregation of variants is not recommended. A key to Xantho sia species in eastern Australia is provided.