Seed mass of Saururus chinensis flowers when the two or three apical leaves that will change colour were subjected to different experimental treatments. Flowers used for the experimental treatment were hand-pollinated. Different letters denote significant differences at P < 0.05. NA, natural; LRBW, leaves were removed just before whitening; LRBWC, leaves were trimmed ~1 mm from their edge just before whitening; LRBR, white leaves were removed just before re-greening; HLRBR, half of each of the white leaves was removed just before re-greening.