The taxonomic relevance of flower colour for (Berberidaceae), with morphological and nomenclatural notes for five species from China.

Morphological variations, particularly flower colour, could be considered as an evolutionarily and ornamentally significant taxonomic criterion for . Our extensive field investigation based on population studies revealed abundant intraspecific variations in flower colour. Five species, (i.e., Franch., Stearn, K.C.Yen, Stearn, and H.R.Liang) were found to possess polymorphic flower colour, which is first described and illustrated here. Moreover, all these species were found to be polymorphic in other diagnostic characters, such as the type of rhizome, the number and arrangement of stem-leaves, and/or their indumentum, which have not been adequately described in previous studies. Therefore, their morphological descriptions have been complemented and/or revised. We also provide notes on the morphology and nomenclature for each species. Additionally, a key to the species in China has been provided. The present study could serve as a basis for understanding their taxonomy and helping their utilisation as an ornamental plant.