A search for the phylogenetic position of the seven-son flower (Heptacodium, Dipsacales): combining molecular and morphological evidence

A first report on the problematic phylogenetic position of Heptacodium (2 s pp.; China) using molecular data from chloroplast DNA is presented. Amplifi cation of ORF2280 homolog region was executed in a number of representative taxa in order to determine if Heptacodium shows similar structural rearran gements as other Dipsacales. DNA sequences of ndhF were generated to clarif y the phylogenetic position of Heptacodium among Caprifoliaceae (s.l.). Six outgroup taxa and fifteen representatives of Dipsacales were sampled and m ore than 2100 basepairs of ndhF sequence were used in a cladistic analysis. Parsimony analysis produced two shortest trees and showed Heptacodium as s ister to all members of Caprifoliaceae (s.str.), although weakly supported. Additionally, trees were constructed with ndhF data supplemented with avai lable rbcL sequences and a morphological data set. Results of all analyses support an unresolved basal position for Heptacodium among Caprifoliaceae ( s.l.), which in part explains the difficulty experienced previously in clas sifying the genus.