Nuclear and plastid DNA sequences confirm the placement of the enigmatic Canacomyrica monticola in Myricaceae

Phylogenetic analyses of DNA sequences of the plastid rbcL gene were used to obtain a phylogenetic frame–work for the New Caledonian endemic genus Canacomyrica (monotypic). A further analysis of selected genera within Fagales combining DNA sequences of the rbcL gene, plastid trnL–F region and nuclear ITS region was also performed. In all analyses Canacomyrica fell into a well–supported clade in which it occupied a position as sister to the remaining genera of Myricaceae. A chromosome number of 2n = 16, consistent with Myricaceae, is reported for Canacomyrica for the first time. On the basis of the phylogenetic data and numerous shared morphological features, the original placement of Canacomyrica in Myricaceae is accepted. Canacomyrica is distinguished from other members of the family by the presence of staminodes in the female flower, a six–lobed perianth and a lamellular, laciniate style. The affinities of Myricaceae within Fagales are re–evaluated in the light of the unusual morphological features of Canacomyrica. The significance of staminodes in Canacomyrica is discussed with reference to pollination syndrome and incomplete suppression of male function in Myricaceae. A lectotype is designated for the name Canacomyrica monticola Guillaumin.