The authors of these novels or poetry collections have chosen their words carefully and wisely. (Don't all authors though?) Certainly poems use a minimum of words to convey feelings and ideas when compared to a full-length novel. Novels in verse employ techniques of poetry in the form and story arc of a novel to tell a story.
To round out this updated list, we've included novels & essays (even a shelf-help book) written by poets plus novels & biographies about poets.