HYDRANGEA serrata
´Bluebird´

A small, up to 1 m tall shrub with stout shoots; leaves dark green and acuminate at the apex; the inflorescence is a corymb appearing in July to August, fertile flowers blue, the large, sterile ray flowers on the outside reddish-purple, in acidic soils light blue - a lovely, free-flowering cultivar. B, K, S. Zone 6a.