Which Tolkien story features the painter Niggle, who must complete a mysterious tree?

Tolkien’s story featuring the painter Niggle and a mysterious tree is Leaf by Niggle.

“Leaf by Niggle” is a short story first published in the Dublin Review in 1945. Its central character is an artist named Niggle who spends so much time perfecting individual leaves that he struggles to complete the larger tree he imagines. The story combines fantasy, moral reflection, and an exploration of artistic creation.

Niggle’s journey after his earthly life leads him to a country where the tree and landscape he imagined become real in a deeper form. The work is often read as Tolkien’s reflection on the relationship between small acts of craftsmanship and larger artistic visions.

The story is sometimes grouped with Tolkien’s children’s fiction, but its tone is more allegorical and contemplative. It is also distinct from “Smith of Wootton Major,” another later short work concerned with imagination and wonder. “Leaf by Niggle” remains one of Tolkien’s clearest fictional discussions of the artist’s unfinished work.