I recently wrote a narrative poem, which is picture book length, but a bit advanced for the picture book set. An editor suggested I might build it into a novel. That idea is a bit daunting, but I've been reading novels in verse to explore the possibilities.
I fell in love with Diamond Willow by Helen Frost. It's quite unusual, with a shape poem on each page based on the shape of the "diamond willow" pattern. Apparently, in the far north, willows that have been scarred sometimes develop a diamond pattern around the wound. This wood is often used to create special objects.
The main character in the book is named Diamond Willow, and the painful scars of her life develop into beautiful new patterns.