As scientists come to better understand how the brain works, the gap between traditional and alternative medicine is narrowing fast. Your Brain on Plants, cowritten by a neuroscientist and an expert in medicinal plants, describes the beneficial effects of more than 70 plants on memory, mind, and mood--from St. John's wort for depression and lavender for stress, to sage for cognitive function and frankincense for an "herbal high."

Expert authors and mother-daughter team Elaine and Nicolette Perry share insights into their own research on how plants can help us sleep, reduce...