Henbane [Greek hyos, hog, and kyamos, bean pod, alluding to use of fruits as hog’s food]

Michael A. Vincent

Herbs, annual, biennial, or perennial, taprooted [rhizomatous], glandular-pubescent [glabrous]. Stems simple or branched. Leaves alternate (basal rosettes and cauline), petiolate (cauline leaves may be sessile or petiolate proximally, sessile distally); blade toothed or lobed. Inflorescences terminal [axillary], racemose [cymose], bracts leaflike. Flowers 5-merous, bilaterally symmetric or slightly irregular; calyx not to slightly accrescent, enclosing fruit, tubular-campanulate [urceolate or cup-shaped], 5-lobed, lobes triangular (lobes shorter than to as long as tube), becoming rigid with rigid or spinescent lobe-tips; corolla yellow or white, throat and veins sometimes purple, bilateral, funnelform; lobes spreading, triangular-ovate, shorter than tube, adaxial lobe usually ± larger; stamens slightly unequal, inserted near base or middle of corolla tube; anthers dorsifixed, ellipsoidal, dehiscing by longitudinal slits (introrse); ovary 2-carpellate, (2-locular); style filiform; stigma capitate, ± 2-lobed. Fruits capsules, ellipsoidal, dehiscence circumscissile. Seeds ovate-subreniform, flattened, (surface reticulate to honeycombed, dull or shiny). x = 14, 17.

Species 23 (2 in the flora): introduced; Eurasia; n Africa; introduced also in South America, s Africa, Australia.

Species of Hyoscyamus sometimes are cultivated as ornamentals. They contain toxic alkaloids, including hyoscyamine and scopolamine, which may have medical applications (M. F. Roberts and M. Wink 1998; W. H. Lewis and M. P. F. Elvin-Lewis 2003).

Lower Taxa

• Hyoscyamus albus Linnaeus
• Hyoscyamus niger Linnaeus