AppearanceHyoscyamus niger is an annual or biennial plant that can grow to 3 ft. (1 m) in height. Foliage The fetid smelling leaves are alternate, simple, toothed, up to 8 in. (20 cm) long and 6 in. (15 cm) wide. In the early season (annual), or first year of growth (biennial) the plant is represented by a rosette. Flowers Flowering occurs in spring to early fall. Flowers are cream to green, five-lobed, 2 in. (5 cm) wide and have purple throats. Fruit Seeds are small and black. Prolific seed production increases the spread of this plant, as a single plant can produce up to half a million seeds.Ecological ThreatHyoscyamus niger is native to the Mediterranean and is poisonous to most mammals. It has been used medicinally for hundreds of years.