"hydrangeas whose blue heads had been famous"
Hydrangeas at Hoveton Hall, Norfolk
Creative Commons AttributionHydrangeas at Hoveton Hall, Norfolk - Credit: Northmetpit

 Hydrangea is a genus of flowering shrubs containing between 70 and 75 species. It is native to southern and eastern Asia and the Americas, but was introduced into Europe in the 18th century. Hydrangeas may be white, pink, blue, mauve, or even red in colour, depending on the species and the type of soil they are grown in. In those Hydrangea species capable of producing blue flowers (such as Hydrangea macrophylla), the blue colour has to be preserved through the maintenance of an acid soil.

 

Hydrangea macrophylla
Creative Commons AttributionHydrangea macrophylla - Credit: Jim Capaldi