Hydrangea is a genus of deciduous or evergreen shrubs, small trees and climbers that are native to Asia, and North and South America. Many species have become popular as cultivated garden plants in many parts of the world. They are favoured for their clustered or flattened umbels of brightly coloured flowers, often comprising a mix of two types: showy, sterile flowers and smaller, less obvious, fertile ones. The commonly grown varieties tend to be deciduous and have good autumn colour. There is a Hydrangea species for just about every garden situation! H. petiolaris is a useful and attractive climber while H.quercifolia and H. paniculata varieties have the best scent. The flowerheads can be used in dried flower arrangements. All parts of the plant are toxic on ingestion and the leaves can aggravate skin allergies.