水杉
The Eastern Asiatic Region is dominated by very old lineages of gymnosperms and woody plant families and is thought to be the cradle of the Holarctic flora. Moreover, this floristic region wasn't significantly glaciated in the Pleistocene, and many relict Tertiary genera (such as "Metasequoia glyptostroboides", ancestors of which were once common throughout the Northern Hemisphere up to subpolar latitudes) found refuge here.