Roberts & Humphreys: Colour in Roses. The Rose Annual (1980) pp. 133-136
Although the flavonoid pigments of a great many garden varieties of roses have been investigated, it would appear from the literature on this subject that investigations on species roses have been far from exhaustive. It is, therefore, quite possible that new pigments still remain to be discovered. Obviously there is considerable interest in whether or not the flavonoid pigment known as delphinidin, which is able to confer a delphinium blue colour, is present in the genus. It has, in fact, been found by the Japanese biochemist Arisumi in the variety 'Samba' (Kordes 1964) but only in the leaves.