Hyoscyamus

Hyoscyamus is a genus of flowering plants in the nightshade family, Solanaceae. The genus includes several species, the most well known being Hyoscyamus niger, commonly called henbane or black henbane. Other species include Hyoscyamus albus (white henbane) and Hyoscyamus reticulatus (nettle-leaved henbane).

These are herbaceous plants native to Europe, North Africa, and western Asia, frequently found in disturbed habitats. They are annual or biennial, reaching up to 1 meter tall. Leaves are large, lobed with irregular teeth; flowers are yellow to greenish with purple veins; fruit is a small inflated capsule containing many seeds.

The plants contain tropane alkaloids, notably hyoscyamine and scopolamine, along with smaller amounts of atropine. These compounds produce anticholinergic effects: pupil dilation, dry mouth, fast heart rate, impaired sweating, delirium and hallucinations at higher doses. They are highly toxic; ingestion of leaves, seeds, or extracts can be fatal, especially for children. Because of toxicity, use is tightly regulated in many countries; historically used in medicine as antispasmodic and sedative, but largely replaced by safer drugs.

Uses and safety: Historically, henbane was used in medicine as an antispasmodic and sedative, and its alkaloids were employed in ophthalmology and anesthesia. In modern medicine, purified hyoscyamine and scopolamine are used in standardized drugs under strict control; whole-plant preparations are rarely used and can be dangerous. The plants are toxic if ingested and can cause confusion, seizures, coma, or death. They are regulated and discouraged for home use.