GABEL, JOHN D.*, DONALD H. LES, W. ALAN CHARLTON, AND ALLEN J. COOMBES. Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043; Department of Biological Sciences, Manchester University, Manchester, M13 9PT, UK; The Sir Harold Hillier Gardens and Arboretum, Jermyns Lane, Ampfield, Romsey Hampshire, SO51 0QA, England, UK. - Phylogeny of Azara (Flacourtiaceae).
Although Flacourtiaceae are often thought of as a highly artificial
family, the genus Azara has long been recognized as a natural
group. Azara is the only genus in Flacourtiaceae to possess
foliar stipules which provide a unifying synapomorphy for the taxon.
Major taxonomic treatments of Flacourtiaceae have placed Azara
in the tribe Flacourtieae along with such genera as
Flacourtia, Dovyalis, Idesia, Olmediella and Xylosma.
However, interspecific relationships in Azara have been poorly
elucidated. Gilg (1925) placed Azara species into three
sections (Microazara, Celastrazara, and Euazara) which
were defined using leaf and stamen characters. The most recent
monograph by Sleumer (1977) also recognized three species groups
within the genus, but these were not formally named. Sleumer defined
these groups using a combination of inflorescence, floral and leaf
characters. Our phylogenetic study combines nuclear and chloroplast
DNA sequences to investigate interspecific relationships in
Azara, and also to evaluate its relationship to other members
of the tribe Flacourtieae. We sequenced the complete ITS
region and trnL (chloroplast DNA) intron for 12 of the 13
Azara species, five other genera of tribe Flacourtieae,
and from Scolopia (tribe Scolopieae). Outgroup
sequences (Salicaceae) were obtained from GenBank. Overall, we find
the groups delimited by Sleumer (1977) to be supported by both
molecular data sets with one slight modification to recognize A.
microphylla as a separate, monotypic group. Molecular data are
also largely congruent with preliminary analyses of morphological
characters in the genus and tribe.
Key words: Flacourtieae, ITS, systematics, trnL