Species in the related genus Schizophragma, also in
Hydrangeaceae, are also often known as hydrangeas. Schizophragma hydrangeoides and Hydrangea
petiolaris are both commonly
known as climbing hydrangeas. There are two flower arrangements in hydrangeas.
Mophead flowers are large round flowerheads resembling pom-poms or, as the name
implies, the head of a mop. Source
