PHYLOGENETIC ANALYSIS OF EUCALYPTUS INFORMAL SUBGENUS SYMPHYOMYRTUS SECTION MAIDENARIA

Eucalyptus informal subgenus Symphyomyrtus section Maidenaria includes 86 currently recognised taxa endemic to south-eastern Australia. Clad istic methodology and a morphological data set have been used to exami ne the phylogenetic relationships of these taxa and an additional two unnamed forms that may be worthy of taxonomic recognition. Maidenaria may be defined as a monophyletic group by the presence of oil glands i n the phloem, although this feature is not unique to the group. Inform al series Ovatae is paraphyletic, having been defined by plesiomorphic features such as petiolate juvenile leaves. Informal series Viminales is monophyletic, defined by juvenile leaves that are opposite, sessil e and cordate for many nodes. The analysis was a difficult one because of a high level of homoplasy (82%), problems with intergrading comple xes of taxa, and coding of characters that are continuously varying. T he cladogram produced for Maidenaria can be viewed as a statement of t he pattern of variation of morphological characters in the group. It i s likely to be only an approximate representation of the phylogeny due to problems of character coding.