All Flesh Is Grass
Millville, USA. A small town like countless others, with people who assume that life as we know it is the only kind of life. If there's anything unusual about the village, it's the strange and beautiful profusion of purple flowers that bloom in nearly everyone's backyard.

To Tupper Tyler, the village idiot, who disappeared into a field of purple blossoms ten years before, they were gentle creatures, the only ones who ever accepted him . . . To Brad Carter, who entered an alternate dimension inhabited by silver-crested men who spoke in music, and primitive, evanescent women, they were a brilliant race looking for a place in the sun ... And to the terror-stricken residents of Millville, they were either an undreamed of link to the future or a frightening, unstoppable force.
Fiction, science fiction, general, Fiction in English, American Science fiction
Clifford D. Simak
Clifford Donald Simak (August 3, 1904 – April 25, 1988) was an American science fiction writer. He won three Hugo Awards and one Nebula Award.The Science Fiction Writers of America made him its third SFWA Grand Master,[4] and the Horror Writers Association made him one of three inaugural winners of the Bram Stoker Award for Lifetime Achievement.[5] He is associated with the pastoral science fiction subgenre.