Family Hydrangeaceae; formerly Saxifragaceae
The common hydrangea with its large mop head, so often seen growing in parks and gardens and offered by florists as a pot plant, is of hybrid origin, mainlyderived from Hydrangea macrophylla, which is a species of Japanese origin. There are two types of hybrids in the group, namely lace caps and hortensia hybrids.
The variety known as 'Blue Wave' is a good example of the Lace Caps, which have dense heads with only a few outer florets showing the petals. The hortensia types have large round heads of sterile flowers with large petals which are fully open over the whole flower head.
