New taxa of Berberis (Berberidaceae) with greenish flowers from a biodiversity hotspot in Sichuan Province, China

A new species, Berberis viridiflora X. H. Li, and a new variety, Berberis sanguinea Franch. var. viridisepala X. H. Li, L. C. Zhang & W. H. Li are described and illustrated from Baoxing County, a biodiversity hotspot located on the eastern edge of Hengduan Mountains in Sichuan Province, Southwest China. Both new taxa resemble B. sanguinea Franch. var. sanguinea, but B. viridiflora differs by the greenish flowers, and the petals being truncate, obtuse, or undulate at apex; while B. sanguinea var. viridisepala differs by the greenish or yellowish green flowers. Morphological features of the pollen grains of B. sanguinea and the two new taxa are revealed by scanning electron microscope. B. sanguinea var. sanguinea displays obvious similarities with a sympatric congener, Berberis multiovula T. S. Ying in the morphology of flowers, stems and leaves, especially its ovule number varies greatly from 2 to 9, thus, B. multiovula characterized by the 5-ovuled ovary is reduced to a synonymy of B. sanguinea var. sanguinea. On the basis of field surveys and study of herbarium specimens, a total of 16 species and varieties of Berberis are recorded from Baoxing County, and a key is provided. Among the 16 taxa, most phenotypic variations in Chinese Berberis can be displayed, including the habit of plants, most morphological variations of stems, branches and leaves, all types of inflorescences, all color types of flowers, and nearly all types of the shape and color of fruits. Baoxing County and its adjacent Sichuan Giant Panda Sanctuaries possibly constitute an active diversification center of Berberis in eastern Hengduan Mountains of China.