Any book that begins with someone hurling from the forest canopy after an encounter with a pit viper can't be all bad. Hansen ("Stranger in the Forest," "Motoring with Mohammed") brings his usual wit, spirit and insight to this latest effort. Largely set in Borneo (where he has been visiting for a decade), the book zigzags from tropical jungle to botanic gardens, convention halls and nurseries in pursuit of orchids. Although you don't have to be interested in these sexy flowers to enjoy the book, it wouldn't hurt.  (GEN112, $13.95)