In Canto One of his poem John Shade (the poet in VN's novel Pale Fire, 1962) speaks of his childhood and mentions hickory leaves and his favorite young shagbark tree:
All colors made me happy: even gray.
My eyes were such that literally they
Took photographs. Whenever I'd permit,
Or, with a silent shiver, order it,
Whatever in my field of vision dwelt -
An indoor scene, hickory leaves, the svelte
Stilettos of a frozen stillicide -
Was printed on my eyelids' nether side