Clethradelavayi is treated here as a single, highly variable species. All characters that have been used to delimit more narrowly defined species in other treatments of Chinese Clethra exhibit a strongly continuous pattern of variation from west to east across the range of the species in China (i.e., leaf size and shape, the number of secondary veins on each side of the midvein, anther size and shape); they also exhibit geographically correlated or seemingly random patterns, but without correlated gaps in character states among any two or more characters (i.e., style pubescence, corolla abaxial surface, stamen exsertion).