PHENETIC AND CLADISTIC RELATIONSHIPS IN COLLYBIA SECT. LEVIPEDES (FUNGI: BASIDIOMYCETES)

Abstract

SummaryPhenetic and cladistic methods were both used to study phylogenetic relationships of fungi in the genus Collybia section Levipedes. Ten North American taxa were scored for 23 morphological and ecological traits, and the resulting data set was used for both kinds of analysis. Essentially identical phenograms were generated regardless of the type of similarity or dissimilarity coefficient used. Both principal coordinate and minimum spanning tree analyses also produced results congruent with the various phenograms. For cladistic analysis, parsimony analysis was chosen to construct Wagner trees, which were rooted using several criteria. With only in‐group taxa in the analysis, a single Wagner tree resulted when the dictum ‘common is primitive’ was used to root the tree. Outgroup taxa were chosen from sections Striipedes, Vestipedes and Maculatae. Of the various runs using outgroup taxa from different sections of Collybia, only that with section Striipedes as outgroup resulted in a single unequivocal tree being resolved. This result is consistent with the hypothesis that Striipedes is most closely allied to Levipedes. All parsimony analyses indicated a high level of parallelism in section Levipedes. Both phenetic and cladistic analyses grouped taxa in a similar manner, although several differences in branching pattern were apparent. The C. dryophila complex was clearly distinguished from the rest of the section by all analyses. Other close relationships were suggested between C. alkalivirens and C. fuscopurpurea, and between C. spongiosa and C. kaufmanii. The Wagner trees are presented as hypotheses of phylogenetic relationship in Levipedes.