Ginseng is any one of the 11 species of slow-growing perennial plants with fleshy roots, belonging to the genus Panax of the family Araliaceae.

Ginseng is found in North America and in eastern Asia (mostly northeast China, Korea, Bhutan, eastern Siberia), typically in cooler climates. Panax vietnamensis, discovered in Vietnam, is the southernmost ginseng known.

This article focuses on the species of the series Panax, which are the species claimed to be adaptogens, principally Panax ginseng and P. quinquefolius. Ginseng is characterized by the presence of ginsenosides and gintonin. Siberian ginseng (Eleutherococcus senticosus) is in the same family, but not genus, as true ginseng.

Like ginseng, it is considered to be an adaptogenic herb. The active compounds in Siberian ginseng are eleutherosides, not ginsenosides. Instead of a fleshy root, Siberian ginseng has a woody root.

Over centuries, ginseng has been considered in China as an important component of Chinese traditional medicine.