Cytogeography of the East Asian Tulips (Amana, Liliaceae)

Amana Honda (Liliaceae), known as ‘east Asian tulips’, is a spring ephemeral genus endemic to Sino-Japanese Floristic Subregion, mainly distributed in eastern and central China, Japan the Korean peninsula. Chromosome numbers are reported here for first time from 89 populations of (representing all seven accepted species, two new species about be published, suspected species). Three ploidy levels found this genus. These diploid (2n = 2x 24) tetraploid 4x 48) widespread A. edulis, while narrow endemics diploid, except one population tianmuensis, which triploid 3x 36). The northernmost southernmost edulis tetraploid, respectively, diploids tetraploids coexist between, with gradual transition latitude increases. This may indicate polyploids have an advantage tolerance environmental stress more adaptable high-temperature environment subtropical regions than diploids. cytotype distributions complex, these results provide hypotheses origins polyploid cytotypes.