quinquefolius

Quinquefolius is a Latin epithet meaning five-leaved and is used in botanical nomenclature to denote species with five leaflets in a leaf. The best-known bearer is Panax quinquefolius, the American ginseng.

Panax quinquefolius is a slow-growing, herbaceous perennial in the Araliaceae family. It has a short, creeping rhizome and a growth habit that forms unbranched or sparsely branched stems. The leaves are palmately compound and typically show five leaflets, though the number can vary with age and genetic variation. The plant produces small, greenish-yellow flowers arranged in branched clusters, followed by bright red berries in late summer or fall. It prefers shaded, rich, well-drained soils in deciduous forest habitats and is native to eastern North America.

Historically, Native American peoples used the root for medicinal and nutritional purposes, and European settlers later adopted it as a traditional remedy. In modern commerce, Panax quinquefolius roots are harvested from wild stands and cultivated plants; large portions of supply come from cultivated sources. The species has faced overharvesting and habitat loss in parts of its range, leading to conservation and regulatory measures in several jurisdictions. In herbal supplements, quinquefolius is marketed as an adaptogen and tonic, though scientific evidence for efficacy is limited, and products vary in quality. As with any medicinal plant, potential adverse effects and drug interactions exist; use should follow medical guidance and regulatory labeling.

Other species may carry the epithet quinquefolius in their names.