Black Henbane

Also known as: insane root. stinking nightshade, fetid nightshade,hog's beam, hogbane, common henbane, poison tobacco.

Black Henbane is a Class C Noxious Weed. The Class C status allows counties to enforce control if locally desired. Other counties may choose to provide education and technical consultation.

Black henbane (Hyoscyamus niger L.), native to Europe, is a member of the nightshade family. In the past, it has been used medicinally and as an ornamental. It is an annual or biennial plant that reproduces solely by seed. The seeds are highly germinable and remain viable in the soil for several years. The plant forms large rosettes with alternate, serrated leaves and develops a fleshy taproot. Mature plants grow up to 3 feet tall. Stems of a mature plant are thick, coarse to tough, and widely branched. Foliage is  abundant and leaves are alternate, oblong to ovate, and coarsely toothed to shallowly lobed. Foliage is covered with fine, sticky hairs and has a foul odor. Flowers are funnel-shaped, 5-lobed, yellowish in color with deep purple veins and throats, and arranged in spike-like clusters. The plant’s pineapple-shaped fruit is about an inch long and contains hundreds of tiny, dark seeds. A single plant can produce 10,000 to 500,000 seeds.

Black henbane is commonly found in rangeland, pastures, roadsides, and waste areas. The plant contains alkaloids that can cause livestock poisoning, although because it is unpalatable, it is seldom grazed. Black henbane is considered poisonous to humans.

Rosette	Flower	Fruit

		Seed
Various stages of seed pods ripening

Physical/Mechanical: Small infestations of black henbane plants can be cut or dug. Moist soil helps to remove the entire tap root system. Removal of the weed should be timed to avoid seed set. If seedpods are present, bag them for proper disposal to avoid further seed dispersal. Mechanical methods, such as mowing, can be difficult when the plant is mature because of its thick, tough stem. Tillage can be effective, but feasibility depends on the type of land infested.

Chemical:  Herbicides used to control black henbane should be applied at the rosette to bolt stage, before flowering. Chemicals to consider include 2,4-D, picloram (provides residual control of germinating seeds the following year), dicamba and metsulfuron (apply at late bolting).

Refer to the label for all herbicides
Always follow label directions prior to use

Biological:  No biological control agents are currently available for control of black henbane.

 

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Questions: contact Steve Van Vleet or phone (509) 397 - 6290