Rosemary Gladstar founded the California School of Herbal Studies in 1978. Later, she and her family established Sage Mountain Retreat Center and Native Plant Reserve in Vermont. She's also an author and she's written a new book, "Medicinal Herbs: A Beginner's Guide". For her, helping people take charge of their own health is part of why she became a herbal expert. Don Merrill talks with her about the ins and outs of herbal medicine, their history, their uses, their benefits and their limitations.