Figure 1
Colour change process of a flower disc in Causonis japonica (flower ID 35 in Table 1). Disc colour changed from orange (a, RGB: 255, 88, 16) to pink (b, RGB: 255, 82, 102) before recovering to orange (c, RGB: 255, 88, 16) again, then pink (d, RGB: 255, 120, 94) again. In the last stage, the flower disc turned brownish pink (e, RGB: 232, 162, 169) then fell off. The two orange colour stages were synchronised with flower sexual activity. (a) First orange stage shows stamen activity (male phase); (c) second orange stage indicates stigma maturation (female phase). Nectar secretion was active only in the orange stages and more active in the female phase; the same tendency was observed in the other cases shown in Table 1.
