Mt, N&SD,Colo,Wyo,Neb,east to NE, Canada. A noxious weed in most States.
Cattle, horses and humans
Black-henbane - Hyoscyamus niger
Tropane alkaloids hyoscyamine, and hyoscine( scopolamine) are found in all parts of the plant. These atropine-like alkaloids act on the autonomic nervous system blocking acetylcholine receptors of parasympathetic postganglionic receptors.
Poisoning is rare in animals as the plant has a strong pungent odor and is not palatable. Human poisoning occurs as result of chewing the flowers, leaves and seeds to experience the halucinogenic effects of the alkaloids.
A large, very hairy, sticky, branching annual or biennial erect herb growing to 5 feet in height. The leaves are alternate, simple, stalkless except at base, coarsely toothed, and 4-8 inches in length. The flowers are greenish yellow or white with prominent purple veins. The flowers are produced in the leaf axils, and each is made up of a 5 lobed calyx. The fruit is a characterisically urn-shaped capsule, the top of which detaches when ripe to release many grey brown, hard seeds.
Decreased salivation (dry mouth), bloat, intestinal stasis, colic, and diarrhea may result
Ataxia due to muscle weakness
Cholinergic drugs such as physostigmine will help reverse the atropine effects.
Animals may exhibit elevated heart rate.
Dilated pupils (mydriasis) are common, and animals may have difficulty seeing normally. Excitement and convulsions may occur when large amounts of plant are eaten
Black henbane is a noxious weed that should be controlled by pulling the plants, mowing the plants to prevent seed formation, and/or using herbicides such a glyphosate.
Black henbane flower
Black henbane fruits
Black henbane dried seed capsules