The Lunatic — Anthony C. Winkler

This novel reveals that lunacy is by no means restricted to the village madman. . . . “By far the funniest book I've read in a decade” (The Washington Post Book World).
 
In Jamaica, Aloysius is tolerated by his neighbors, but forced to eke out a living by doing odd jobs and use the hospitable woodlands for shelter. Starved of human companionship, he has running conversations with trees and plants.
 
Then love, or a peculiar version of it, comes to Aloysius in the form of a solidly built German lady, Inga Schmidt, who has come to the Caribbean to photograph the flora and fauna. They will embark on a romance and a series of misadventures that may turn the island, and their lives, upside down . . .
 
“Every country (if she's lucky) gets the Mark Twain she deserves, and Winkler is ours, bristling with savage Jamaican wit.” -- Marlon James