Plant Systematics and Evolution

, Volume 196, Issue 3, pp 173–183

Morphological and molecular comparisons ofCampsis grandiflora andC. radicans (Bignoniaceae), an eastern Asian and eastern North American vicariad species pair

  • Jun Wen
  • Robert K. Jansen
Article

DOI: 10.1007/BF00982958

Cite this article as:
Wen, J. & Jansen, R.K. Pl Syst Evol (1995) 196: 173. doi:10.1007/BF00982958

Abstract

Morphological and molecular comparisons were made forCampsis grandiflora (Thunb.)K. Schumann (Bignoniaceae) from eastern Asia andC. radicans (L.)Seemann from eastern North America. Chloroplast DNA (cpDNA) variation was surveyed with 20 restriction endonucleases. The cpDNA divergence between the two vicariad species was 2.44%, which is the highest reported among North Temperate disjunct taxa and one of the highest reported for infrageneric taxa. Detailed morphological comparisons also suggest a high level of divergence. Cluster analyses based on 22 morphological characters and 39 OTUs revealed two distinct groups corresponding with the two species. The average taxonomic distance between the two species was 1.806. Analyses of variance (ANOVA) revealed that 12 of the 18 quantitative characters differed significantly (α ⩽ 0.01) betweenC. grandiflora andC. radicans. Divergence time based on cpDNA data was estimated as 24.4 million years. The Bering land bridge hypothesis was favored over the North Atlantic land bridge hypothesis based on the estimated divergence time and the geological history of the North Temperate region. The high levels of morphological and cpDNA divergence are not consistent with morphological stasis, which has been proposed as a common mode of evolution for North Temperate disjunct taxa.

Key words

BignoniaceaeCampsisMorphological stasismorphologychloroplast DNAdisjunctionFlora of eastern Asiaeastern North America

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Jun Wen
    • 1
  • Robert K. Jansen
    • 2
  1. 1.Laboratory of Molecular SystematicsSmithsonian InstitutionWashington, DCUSA
  2. 2.Department of BotanyUniversity of TexasAustinUSA