Most of the flowers in the thistle family bloom on prickly plants in shades of white, yellow, pink and red. The blue type is the exception – with soft leaves and blue blossoms. Nevertheless, they belong to the same family, as determined by the structure of the inflorescence.
The color blue is rare in the world of flowers and usually appears in families that are more evolutionarily evolved and on high mountains. It is presumed that because the chemical compounds of the color (anthocyanins) absorb ultraviolet irradiation, the pollen grains are protected from their harmful effect as well as the fact that the flowers can be seen better by bees.
Issue: April 2018
Other Philatelic products issued April 2018