With this plant of moist soils to wet watersides the flower-colour depends on the place of growth. After the nodding trusses of bell-shaped flowers often smooth, black, nut-like fruits are formed. The plant produces upright stems with slightly rounded and stalked leaves beneath and un-stalked, more elongated leaves above. The flower-stems are hollow and the plant grows from a sap-root. It is endemic in Europe, but naturalized in other parts of the world. The sap enhances the cure of wounds. For a spot in sun to light shade and fertile, moist to wet soil. Perfectly winter-hardy.