ヤグルマギク
The pollen of "Centaurea cyanus" is used by several different insect species. Insects of the orders Hymenoptera and Diptera are particularly attracted by the flower. As "Centaurea cyanus" is a self-incompatible species, it needs external pollination. The nectar of "Centaurea cyanus" is very sweet with a sugar content of 34 %. Due to its high sugar production of up to 0.2 mg sugar per day and flower, the species is highly appreciated by beekeepers.