Evolutionary history and climate conditions constrain the flower colors of woody plants in China

Abstract

Abstract Aim In this study, we investigated (1) the differences in flower color composition among growth forms of woody plants in China and (2) the influences of biogeographic regions, evolutionary age, and climatic conditions on geographic variation in the proportions of different flower colors. Methods Using distribution maps and flower color information (white, red, yellow, yellow-green, green, and blue-purple) of 7673 Chinese woody plant species and a dated genus-level phylogenetic tree, we compared flower color composition among different growth forms (shrubs, trees and lianas). We further estimated the relationships of geographical patterns in the proportions of different flower colors with seven different biogeographic regions, evolutionary age, and different contemporary climatic variables. Important Findings Compared with trees or lianas, shrubs showed a higher proportion of species with anthocyanin-based red and blue-purple flowers. The geographic patterns of flower color composition of woody plants in China were strongly influenced by regional effects and contemporary climate, especially precipitation and ultraviolet B irradiance. The proportion of species with presumably bee-pollinated yellow and blue-purple flowers and stress tolerant anthocyanin-based red and blue-purple flower colors tended to be high in the northwestern part of China. Green flowers tended to evolve earlier than others, but evolutionary age had quite weak influences on the geographic pattern of flower colors. Our results reflect both evolutionary and environmental constraints on the distribution of flower colors of woody plants in China.