While the colour of flowers affects interactions with pollinators, other pigments confer invisible traits such as protection against ultraviolet (UV) radiation. In this study, researchers investigated the UV absorbance of plants in the Potentilleae tribe of the rose family, and tested whether UV floral patterns were associated certain geographic or climatic properties. Initially, the researchers constructed a phylogeny of the tribe through alignment of DNA sequences from 130 species herbaria. They then assessed the absorptive properties of 177 different species by photographing flowers under UV light and measuring proportion of petals absorbing UV. They find that UV absorption is mostly present in plants with yellow petals, and although unable to predict the presence or absence of absorption by means of geography or climate, they do find that among plants that absorb, those growing in areas with high level of UV exposure have more uniform patterns of absorption.
Koski MH and Ashman T-L (2016) Macroevolutionary patterns of ultraviolet floral pigmentation explained by geography and associated bioclimatic factors. New Phytologist. Wiley-Blackwell, 708–718. Available at doi:10.1111/nph.13921.