Hydrangea flower is by far the greatest species diversity is in eastern Asia, notably China and Japan. Hydrangea flowers are produced from early spring to late autumn.
Hydrangeas are one of very few plants that accumulate aluminium. Aluminium is released from acidic soils, and in some species, forms complexes in the hydrangea flower giving them their blue colour.
In Victorian England times, to send someone hydrangeas flower was to suggest that person had been boasting".