|The cultivar, 'Rosalba' is a deciduous, upright shrub with slender stems and pointed, 6 inch long, ovate leaves, which are much more narrow than its Bigleaf Hydrangea relatives. Foliage turns red in fall. Flowers are held in flat, 2 to 4 inch wide, lacy corymbs and borne from summer to fall. Native to Korea and Japan.
H. serrata is loosely related to the Bigleaf Hydrangeas, but has a more delicate appearance, with slender stems, narrow leaves and smaller flowers. It is native to mountain woodlands of Japan and Korea and is hardier in constitution than H.macrophylla. Grows to 3 to 5 feet in height, with flower color ranging from blue to pink to crimson.