Hydrangea macrophylla
The young leaves, when dried and rubbed between the hands, become very sweet and are used to make a sweet tea called 'tea of heaven', it is used in Buddhist ceremonies.
The leaves contain phyllodulcin (its chemical formula is C16 H14 O), a very sweet substance that can be used as a sugar substitute. One small leaf is sufficient to sweeten a cup of tea.
The older leaves can be dried, powdered and used as a flavouring in foods.
The young leaves and shoots are also eaten cooked.
Young leaves contain the toxin hydrocyanic acid, this reduces as the leaves grow older, often to zero levels.
The leaves, roots and flowers are a said to be a more potent antimalarial than quinine, due to the presence of an alkaloid.