Fig. 2From: Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolationTwo-dimensional scatter diagram of the first and second components from the PCA using 10 morphological characters (a), and petal reflectance spectra (b) in B. alternifolia, B. crispa, and B. × wardii. Pink squares, green circles and calamine blue stars represent B. alternifolia, B. crispa and B. × wardii, respectivelyBack to article page