Roses aren't blue, yet

Red roses and blue cornflowers share a common chemistry - the pigment anthocyanin. But, in the red rose it appears red and in the blue cornflower…blue. Now, a Japanese team led by Masaaki Shiono of Kyushu University have discovered why. Cornflowers, they found, build a supramolecular complex from six anthocyanin groups bound to a flavone together with an iron, a magnesium and two calcium ions. Roses do not. The discovery might one day allow plant researchers to breed or engineer a new variety of rose with true blue flowers, something gardeners and plant lovers have sought for decades if not centuries.