In his first book of new poetry since Sumerian Vistas (1987), A.R. Ammons, one of America's greatest living poets, uses an unlikely subject - garbage - as the occasion for a profound and often funny meditation on nature and mutability. Driving along I-95 in Florida the poet sights a smoldering mountain of the stuff and is moved to muse: "garbage has to be the poem of our time because / garbage is spiritual, believable enough to get our attention,...