Abstract: The author infered that some two ancient species of Meta-sequoia and Sequoiadendron, whose direct descendants were probably M. glyptostroboides and S. giganteum, might be the parents of Sequoia semper-uirens. According to the previous result and Florin's paleobotany data, the present paper conjectured that the years and locality of hybridizational origin of autoallopolyploid (AAAABB) S. semperuirens might be in (1) Miocene, West America (take Oregon and its neighbourhood as the center) (Fig. 1-3), (2) Paleocene, the west coast of Greenland (Fig. 1-5); (3) late Cretaceous, Central-West America (including Wyoming, Colorado) (Fig. 1-4). The present author here considered that the possibility of the first conjecture was greater possible than the other two.

Key words: Sequoia sempervirens