Pound for pound, what's the most valuable plant in Pennsylvania forests? If you said "walnut" or "cherry," guess again. It's the root of a small, green plant called ginseng. Hong Kong markets pay big bucks for wild Pennsylvania "sang," used in traditional medicine. In this installment of our series, Pennsylvania Radio Expeditions, WPSU's Cynthia Berger visits a patch of the uncommon and vulnerable plants with Penn State ginseng expert Eric Burkhart.