Is is Philip J.(lol) Farmer's "The Stone God Awakens"?
Per Amazon;
Ulysses Singing Bear is a 20th century scientist that becomes frozen in an "instant of time" as a result of a scientific experiment that goes very wrong. Fast-forward a million years and "somehow" the stone god, as Ulysses has been referred too down through the eons, becomes unfrozen. He finds warring races of intelligent, but technologically primitive beings evolved from cats, raccoons, monkeys, bats, elephants etc, dominating this future. Ulysses pulls off a masterful deception and insures his survival by convincing the natives that his reinvention of military weapons: bows and arrows and gunpowder are manifestations of his "god-like" powers. Eventually he sets out on a journey to find other humans. In order to reach the coast, where he surmised men would dwell, he must transverse The Tree. This massive plant is several miles high, spreads out hundreds of miles and is inhabited by a host of deadly plants, animals and warring clans.
