Ginseng is any one of eleven distinct species of slow-growing perennial plants with fleshy roots, belonging to the Panax genus in the family Araliaceae. It grows in the Northern Hemisphere in eastern Asia (mostly northern China, Korea, and eastern Siberia), typically in cooler climates; Panax vietnamensis, discovered in Vietnam, is the southernmost ginseng found. This article focuses on the Series Panax ginsengs, which are the adaptogenic herbs, principally Panax ginseng and P. quinquefolius. Ginseng is characterized by the presence of ginsenosides.
Siberian ginseng (Eleutherococcus senticosus) is not a true ginseng, but a different plant that was renamed as "Siberian ginseng" as a marketing ploy; instead of a fleshy root, it has a woody root, and instead of ginsenosides, eleutherosides are the active compound. Eleutherosides are classified as another adaptogen. (see below).