Black Henbane

Black Henbane (Hyoscyamus niger)

Black HenbaneBACKGROUND: Black henbane (Hyoscyamus niger) is a Mediterranean native that was introduced as an ornamental and medicinal plant in the 17th century. It spreads by seeds and is found in a variety or environmental conditions. Black henbane is narcotic and poisonous to humans. Livestock avoid it unless other forage is not available. Two alkaloids in black henbane tissues (hyoscyamine and scopolamine) are useful sedative/ anti-spasmodic drugs when used under controlled conditions.

Black HenbaneDESCRIPTION: Black henbane is an annual or biennial plant that grows up to 3 feet tall. The entire plant is covered with greasy hairs. Leaves are up to 8 inches long and 6 inches wide, shallowly lobed, and heavy scented. Flowers are borne on spikes form the leaf axils from May until September. They are showy, 5 lobed, up to 2 inches across, and greenish-yellow in color with deep purple veins and throats. The calyx forms a 1-inch, urn-shaped “fruit” that has a thickened lid that pops off at maturity and spills the black seeds.

DISTRIBUTION: Black henbane is found in the northern U. S. and southern Canada.

CONTROL: No biological control agents are available for control of black henbane, but herbicides can provide excellent control.

Black Henbane Distibution Map - Grey Area 


© 1999 University of Idaho: Text and photographs for these pages from Idaho’s Noxious Weeds, by Robert H. Callihan and Timothy W. Miller (revised by Don W. Morishita and Larry W. Lass).

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