A crown made of aspen leaves was said to give its wearer the power to visit and return safely from the Underworld. Aspen crowns found in ancient burial mounds may have been included to allow the spirits of the deceased to be reborn. Aspis, the aspen's Greek name, means shield, which was one of the many traditional uses of its wood.
In Celtic mythology, the visual effect of an aspen trembling in the wind was said to be the tree communicating between this world and the next. Ref: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/aspen/
Where to see it? Wakehurst Place, West Sussex 16 August 2020