J Syst Evol ›› 2018, Vol. 56 ›› Issue (4): 394-400.DOI: 10.1111/jse.12303

• Short Communication • Previous Articles    

Structure and ontogeny of successive cambia in Tetrastigma (Vitaceae), the host plants of Rafflesiaceae

Marcelo R. Pace1*, Veronica Angyalossy2, Pedro Acevedo-Rodríguez, Jun Wen1   

  1. 1Department of Botany, National Museum of Natural History, Smithsonian Institution, Constitution Avenue & 10th street NW, MRC-166, Washington, DC 20560, USA
    2Laboratório de Anatomia Vegetal, Departamento de Botanica, Universidade de São Paulo, Rua do Matão, 277, Cidade Universitária, São Paulo, S.P., 05508-090, Brazil.
  • Received:2017-12-13 Accepted:2018-01-29 Published:2018-07-10


Successive cambia in Vitaceae have been reported solely for Tetrastigma, a diverse genus of lianas found primarily in tropical Asia, extending into Australia. However, the structure and origin of these successive cambia have never been fully studied. Here we report the presence of this cambial variant in Tetrastigma retinervum and T. voinierianum, and describe its ontogeny in detail in the latter. New cambia appear successively in stems of Tetrastigma differentiating from the innermost parenchyma cells of the primary phloem, which are located interior to the pericyclic fiber strands. This study constitutes the first report of successive cambia being derived from primary phloem parenchyma in woody plants as a whole. Both species are members of Tetrastigma clade VI, the most species‐rich lineage within the genus. The examination of mature stems of additional species of Tetrastigma should determine the distribution of this unique type of cambial variant in the genus and enhance our understanding of the adaptive significance of this unusual character.

Key words: cambial variants, lianas, successive cambia, Tetrastigma, variant secondary growth, vines, Vitaceae, wood and bark anatomy.