Can you help me identify this fantasy book that is based in a world where the people are plants? I think the book is written by two authors and there was some kind of plot twist at the end where the two main characters have sex and by doing so, some kind of important information is released and they save the world.
Piers Anthony and Jo Anne Taeusch The Secret of Spring.
Spring is a sorcerer's daughter. The sorcerer locks some information within his daughter. The sorcerer dies, and an ambitious wizard "will do anything to get [Spring's secrets]... including the obvious". - from the back cover. Herb Moss is a sentient plant who romances Spring.