Japanese consider Ajisai Hydrangea involucrata  to be the quintessential flower of June. Many different varieties of hydrangea have been developed of various colors, though the original ones the flowers were usually blue.  Hydrangea have another Japanese name, however, nanahenge meaning seven transformations, deriving from unique characteristics of the flower, that is, the colors of the petals change according with the chemical makeup of the soil! This feature has given the flower symbolic meaning in Japanese poetry and literature, usually used to convey a fickle heart. Its scientific name, otaksa hortensia. The flowers usually follow either the pom pom variety of mophead style.  German naturalist P.F. von Siebold, who introduced Hydrangeaceae to Europe from Japan.