A natural history and ecological survey of the bristlecone pine, celebrated as the earth's oldest living thing. Cohen, a professor of literature, considers too the cultural significance and aesthetics of the bristlecone. With illustrations by Valerie Cohen. The best places to see bristlecones is Inyo National Forest in California or at several sites in the Great Basin. The tree ranges from California's Wite Mountains, into Nevada and Utah, south into the Sangre Christo mountains.  (SWU52, $34.95)