Phylogenetic relationships in the Hamamelidaceae: evidence from the nucleotide sequences of the plastid gene matK

The Hamamelidaceae is a family that bridges the basal elements of the Rosid ae and the "lower" Hamamelidae, thus a better understanding of the phylogen y of the family is important for clarifying evolutionary patterns in the di versification of eudicots. However, subfamilial as well as tribal relations hips in the Hamamelidaceae have been controversial. Nucleotide sequences of the chloroplast gene matK were used to study the intergeneric relationship s of the family. In the phylogenetic trees, constructed using parsimony ana lysis, the clade containing Altingia and Liqui dambar (Altingioideae) is si ster to a clade that includes all other Hamamelidaceae. Exbucklandia and Rh odoleia form a clads, suggesting a close relationship between the two gener a. Disanthus is sister to the monophyletic Hamamelidoideae. The paraphyleti c arrangement of Disanthus, Mytilaria and Exbucklandia with respect to the Hamamelidoideae does not support the combination of these genera in one sub family. In the Hamamelidoideae, the matK phylogeny supports the monophyly o f several previously recognized groups with modifications, including the tr ibes Eustigmateae (incl. Molinadendron), Fothergilleae (excl. Molinadendron and Matudaea), and the subtribe Dicoryphinae. However, the Hamamelideae as traditionally circumscribed is polyphyletic. Apetaly has evolved three tim es independently in the Hamamelidoideae.