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Phylogeny of Pericallis (Asteraceae): a total evidence approach reappraising the double origin of woodiness
Author(s) -
Swenson Ulf,
Manns Ulrika
Publication year - 2003
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.2307/3647452
Subject(s) - biology , monophyly , character evolution , clade , taxon , maximum parsimony , molecular phylogenetics , phylogenetic tree , genus , phylogenetics , evolutionary biology , botany , zoology , gene , biochemistry
We report the results from parsimony analyses of all 14 recognized species in Pericallis (Asteraceae, Senecioneae), one based on morphology and one based on combined data from morphology and molecular sequences of the nuclear internal transcribed spacer (ITS) using gap coding. Pericallis is restricted to the Macaronesian archipelago in the Atlantic Ocean. Recently it was suggested that woodiness, a character frequently developed in vascular plants on oceanic islands, evolved twice in Pericallis and that the genus had a New World biogeographic affinity. A morphological study was therefore pertinent to test if the hypothesis of multiple origins of woodiness is supported by morphology and/or total evidence. Our results show an evidently young taxon with many polymorphic characters. Monophyly of Pericallis is strongly supported and a close relationship with the African genus Cineraria is suggested. It therefore seems plausible that Pericallis has a biogeographic affinity to Africa rather than to the New World. Morphology alone indicates that the ancestral state for Pericallis was woody. Combined data are indecisive if woodiness evolved several times, but an alternative explanation is that woodiness might have been a plesiomorphic character state present in a shrubby ancestor that once colonized Macaronesia. The herbaceous habit is a novelty, derived from woody ancestors. Pericallis tussilaginis , a herbaceous species, embodies conflicting phylogenetic signals; further research is needed to understand its origin. A clade of five taxonomically complex herbaceous species is postulated to have had recent origin and undergone rapid diversification.