Doubts that glands of calyx of cleistogamic Malpighiaceae serve as protection.
Some species of Solanum bear long- and short-styled flowers on same plant.
Changing colours of some flowers may show insects the proper moment for fertilisation.
Doubts that the style of Pontederia cordata changes length.
Sexual difference in wings of some butterflies due to development in male of scales that emit odours to excite female.