@ARTICLE{TreeBASE2Ref18781,
author = {Lei Xie and Jun Wen and Liang-Qian Li},
title = {Phylogenetic analyses of Clematis (Ranunculaceae) based on sequences of nuclear ribosomal ITS and three plastid regions.},
year = {2010},
keywords = {},
doi = {},
url = {},
pmid = {},
journal = {Systematic Botany},
volume = {},
number = {},
pages = {},
abstract = {Clematis, a largely temperate genus of vines and lianas, consists of approximately 300 species. Based on a sampling from all continents, sequences of the nrITS, the plastid atpB-rbcL spacer, psbA-trnH-trnQ spacer, and rpoB-trnC spacer regions were analyzed using parsimony, maximum likelihood, and Bayesian inference methods. Analysis of the combined data set using parsimony, maximum likelihood, and Bayesian inference methods yielded similar topologies. Previously recognized genera including Archiclematis and Naravelia are nested within Clematis, supporting the merging of these genera within Clematis. Ten major clades with various levels of support were detected in the combined analyses. Our results in general do not support previous infrageneric classifications based on morphological characters and suggest significant convergence in floral and vegetative characters in Clematis. Several clades were resolved as regional geographic groups. Bayesian dating suggests a relatively ancient origin of the genus in the Oligocene, yet a relatively recent species radiation of the crown Clematis in the Miocene. Geologic and climatic changes in the late Tertiary are perhaps important for the speciation of Clematis, especially in eastern Asia. Long-distance fruit dispersal of the fruits by wind, water, and/or animals, and strong environmental adaptability are proposed as the main mechanisms for the current cosmopolitan distribution and high species diversity of Clematis.}
}