A genus of the figwort family (Scrophulariaceae) ranging from the Canary Islands to central Asia. Foxglove (Digitalis purpurea), a native of western Europe, is the source of the important drug digitalis, much used in the treatment of heart disorders. Fresh, mature leaves are carefully selected, quickly dried, and stored in airtight containers. The active ingredient of digitalis is the glucoside digitalin. This slows and regulates the heartbeat, improving the tone and rhythm, and making the contractions more effective. The plant is also prized as a herbaceous perennial.