When Deborah Davis was just seven years old, her mother read her a book about adoption, gently explaining to the mystified child that her origins made her special. For Davis, the revelation of this truth set in motion a consuming curiosity about her birth parents. Ultimately, it led to the author's exhaustive search to identify and meet the two individuals who were biologically closest to her, yet had made the decision to give her away.

"The Delta Poinsettia" is Davis's candid, tender tale of tracking down the biological parents who went to great lengths to remain beyond her grasp. Her...