Black henbane
Discuss this plant with the guide — choose this profile as a possible match and prepare your observations for Colorado Plants & Practical Care.
Hyoscyamus niger
Colorado noxious weed · List B — Stop the spread. CO-rules-2025
Established in some areas. Requirements vary by location: eradication, containment or suppression to stop further spread. This is a management category, separate from danger ratings. Category source · What the lists mean.
Highly poisonous; keep animals away. Exposure help.
Still researching this plant
This is a sourced working profile. The cited findings are available below. Independent botanical and veterinary review is pending. Uncertainty is not a finding that the plant is safe.
Three views of this plant
Source-identified reference photographs; these are not a complete identification key. A source location outside Colorado does not establish local occurrence.
H. Zell · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Hyoscyamus niger , Solanaceae, Henbane, Stinking Nightshade, flowers; Botanical Garden KIT, Karlsruhe, Germany. The whole, fresh, blooming plant is used in homeopathy as remedy: Hyoscyamus (Hyos.) Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Stefan.lefnaer · CC BY-SA 4.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Stem with glandular hairs Taxonym: Hyoscyamus niger ss Fischer et al. EfÖLS 2008 ISBN 978-3-85474-187-9 Location: S Hollabrunn, district Hollabrunn, Lower Austria - ca. 220 m a.s.l. Habitat: pumpkin field Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Bjoertvedt · CC BY-SA 3.0
Photo source and identification
Original record · Original image
Source-identified photograph with visual consistency check Photo of Hyoscyamus niger (norwegian: bulmeurt) at the island og Hovedøya, in the inner Oslofjord, Norway. Source labeling and visible consistency checked; not an independent specimen determination.
Wikimedia-generated thumbnail rescaling only; downloaded bytes unchanged. Gallery display preserves the full image; the catalog preview uses a CSS crop.
Recognize
A coarse, hairy annual or biennial with sticky-looking leaves and yellowish flowers marked by purple veins. N-hyoscyamus-niger
Plants & habitat
Self-seeding produces persistent infestations on disturbed ground. Prevent mature fruits from scattering seed. N-hyoscyamus-niger
People
Tropane alkaloids can cause severe poisoning, including convulsions and coma. Do not taste or use it as a home remedy. N-hyoscyamus-niger
Dogs & cats
NC State flags dogs and cats. Treat suspected ingestion as urgent and contact a veterinarian. N-hyoscyamus-niger
Other animals
The source reports particular seed toxicity to pigs and flags horses. Animal avoidance is not a guarantee against poisoning. N-hyoscyamus-niger
Before taking action
Confirm identification and the requirements of your county weed program. For chemical treatment, follow the current product label, including restrictions around animals and water. S27
References
- CO-rules-2025 — Colorado Noxious Weed Act rules, 8 CCR 1206-2, Colorado Secretary of State / Department of Agriculture. Accessed 2026-09-07T01:07:48+00:00. Locator: Parts 3.1, 4.1, 5.1; management provisions; effective May 15, 2025.
- N-hyoscyamus-niger — hyoscyamus niger — Plant Toolbox, NC State Extension. Accessed 2026-09-07T01:04:53+00:00. Locator: Description; Attributes; Problems; Poisonous to Humans.
- S27 — 2103 – Colorado Noxious Weeds, PlantTalk Colorado · CSU Extension. Accessed 2026-09-07T00:23:57+00:00. Locator: List A, B and C management categories.