J Syst Evol ›› 2018, Vol. 56 ›› Issue (4): 360-373.DOI: 10.1111/jse.12309

• Research Articles • Previous Articles     Next Articles

Evolutionary trends in Tetrastigma (Vitaceae): Morphological diversity and taxonomic implications

Sadaf Habib1,2, Viet-Cuong Dang1,2,3, Stefanie M. Ickert-Bond4, Jun Wen5, Zhi-Duan Chen1,3, and Li-Min Lu1,3*   

  1. 1State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China
    4UA Museum of the North Herbarium and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775-6960, USA
    5Department of Botany, National Museum of Natural History, MRC 166, Smithsonian Institution, Washington DC, 20013-7012, USA
  • Received:2017-12-28 Accepted:2018-02-12 Published:2018-07-10

Abstract:

Tetrastigma (Miq.) Planch. (Vitaceae) is a genus with ca. 100 species showing great morphological diversity. Previous molecular phylogenetic studies suggested that traditional classification systems are not consistent with the molecular phylogeny, and Tetrastigma is undergoing further systematic investigation. We traced the evolutionary trends of 20 morphological characters within a robust phylogenetic framework. Our results revealed that many morphological characters show either multiple transitions or few state changes, however, some characters show distinct variation. The two subgenera in Tetrastigma (subgen. Tetrastigma and subgen. Palmicirrata) based on unbranched/bifurcate versus digitately branched tendrils are not supported because subgen. Tetrastigma is paraphyletic. However, the unbranched versus bifurcate/digitately branched tendril is of taxonomic utility to characterize some of the major clades. Inflorescences in Tetrastigma appear axillary, but are leaf‐opposed on a compressed axillary shoot. We found most of the species in Tetrastigma retained the ancestral compound dichasial inflorescence, except those of clade IV that have derived pseudo‐umbellate inflorescences. Other characters including habit, leaf organization, and berry shape provide additional morphological support for the major clades. Our morphological analysis and recent molecular study suggest each of the five major clades within Tetrastigma be treated as distinct taxonomic sections (five sections in the genus).

Key words: classification, molecular phylogeny, morphological evolution, Tetrastigma, Vitaceae.