Hyoscyamus niger

Illustrator: Yevonn Wilson-Ramsey

Copyright: Flora of North America Association

Herbs annual or biennial, 0.3–1.2 m, aromatic. Stems simple or branched. Leaves: proximal cauline leaves petiolate, mid and distal cauline leaves sessile; blade broadly lanceolate to ovate, 5–30 × 2–15 cm, base clasping, margins coarsely toothed or shallowly to deeply lobed, lobes pinnate, narrowly triangular, 0.5–5 cm, apex acute. Flowers: calyx 8–15 × 5–10 mm, lobes triangular, apically acute-acuminate; corolla pale yellow to greenish yellow with purple throat and veins, 25–45 × 23–43 mm, tube narrow, 8–12 × 4–5 mm, lobes broadly triangular-ovate, 5–7 × 6–10 mm, apically rounded, acute, or emarginate, abaxially often glandular-hairy in proximal half; stamens 7–8 mm; filaments 5–7 mm; anthers 2.1 × 1.1 mm; ovary 2–3 × 2–2.5 mm; style 10–12 mm.

Phenology: Flowering May–Sep.
Habitat: Waste places, roadsides, fields.
Elevation: 0–2900 m.

Distribution

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Introduced; Alta., B.C., Man., N.B., N.S., Ont., P.E.I., Que., Sask., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Maine, Md., Mass., Mich., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.Dak., Oreg., Pa., S.Dak., Utah, Vt., Wash., Wis., Wyo., Eurasia, intro­duced also in South America, s Africa, Australia.

Discussion

Hyoscyamus niger is highly toxic and should not be ingested. It contains the alkaloids hyoscyamine and scopolamine in all parts of the plant (W. H. Blackwell 1990). These compounds, as well as atropine and others, have medicinal applications, due in part to their activity as acetylcholine depressors, perhaps for treatment of certain heart conditions, as antispasmodics, to reduce symptoms of emphysema, and to relieve toothache (G. M. Hocking 1947; W. H. Lewis and M. P. F. Elvin-Lewis 2003).

Collections of Hyoscyamus niger from Nova Scotia and Prince Edward Island appear to be waifs.

Selected References

None.

Lower Taxa

None.