Plants evolve multiform defense mechanisms for dealing with herbivories in the interest of least damages caused
by herbivores. It. s beneficial to plants by signaling defensive commitments to potential herbivores when plants are constantly
sampled by herbivores. Colour, a kind of stable and effective visual signal which is epigamic to animals for pollination
and seed- dispersal, sometimes could become aposematic signal to herbivores. After sampling and avoidance learning,
herbivores can discriminate this signal and associate it with unpleasant experiences, so aposematic coloration comes into
being between plan-t animal interaction. The theory of aposematic coloration has not been accepted in plants while it has
been adequately discussed for a long time in animal kingdom until Hamilton. s signal theory about autumn colours was published.
Pushed by Hamilton. s theory, some botanists have discovered and testified aposematic coloration do exist in plants
such as autumn leaves, young leaves of tropical rainforests, some thorny plants and reproductive organs of plants whereas
some of them are still obscure or controversial. Aposematic coloration should not only belong to animals, plants could evolve
it too if necessary for plant fitness. The temporal and spatial colour polymorphism in vegetative parts of plants deserve more
research and the defense tradeoff hypothesis predicts the possibility of aposematism may occur in the reproductive organs ofplants.
Scientists would comprehend the complicated plan-t animal interactions better and more via the research of physiological
and ecological adaptive significance of plant showy colours which ex ist in leaves and reproductive parts.