Plant Diversity ›› 2005, Vol. 27 ›› Issue (05): 449-470.

• Articles •     Next Articles

Fossil History of Some Endemic Seed Plants of East Asia and Its Phytogeographical Significance

ZHOU Zhe-Kun1, Arata Momohara2   

  1. 1 Kunming Institute of Botany , Chinese Academy of Sciences, Kunming 650204 , China;
    2 Faculty of Horticulture , Chiba University , 648 Matsudo , Chiba , 271 - 8510 , Japan
  • Received:2005-04-29 Online:2005-10-01 Published:2005-10-01
  • Contact: ZHOU Zhe-Kun

Abstract: Endemic elements are crucial for floristic and phytogeographical analysis . The levels of endemicity are important foundation of dividing floristic regions, different floristic ranks based on different endemic levels . The fossil history of endemic families and genera to the East Asia Floristic Kingdom play an
important role in understanding the origin , development and differentiation of this flora kingdom . The fossil history of five endemic families (Cercidiphyllaceae, Eucommiaceae , Ginkgoaceae, Sargentodoxaceae and Treochodendraceae ) and 20 endemic genera ( Cathaya , Cephalotaxus, Corylopsis, Craigia , Cuninghamia, Davidia , Dipteronia , Emmenopterys , Exbucklandia , Fokienia , Fortunearia , Glyptostrobus, Keteleeria , Metasequoia , Pseudolarix, Platycarya , Shaniodendron , Sinowilsonia , Tapiscia , Toricellia and Taiwania) are reviewed . The fossil history shows that these endemic plants have three resources, one from Arctic-Tertiary , one boreotropic and one East Asia . This indicates that East floristic combination are a complex in its origin . Above mentioned three elements would be their three of resources. All endemic plants had much wider distributions in geological time . Their distributions were reduced during long geological time and become endemic to East Asia in the late Pliocene or early Quaternary . If the levels of endemism are really important foundation for dividing floristic regions, the time of formation of endemicity would be the time of formation of the floristic regions . The modern East Asia plant kingdom
would be formed in the late Pliocene or early Quaternary .

Key words: Endemic plants