Black henbane
(Hyoscyamus niger)
An annual or biennial plant 1-3 feet tall with hairy, shallowly lobed leaves and brownish yellow flowers with a purple center and purple veins. All foliage has a foul odor and is toxic to both humans and livestock. This weed tends to invade disturbed or overgrazed sites. It can grow in most soil conditions but prefers moist, sandy, or well-drained loams.
Due to the foul odor of the plant, it is not normally consumed by livestock unless there is no other available forage. It is relatively rare but has been found in Gibson Gulch west of Divide Creek. There have also been reported cases just west of the West Fork of Stewart Gulch on the Roan Plateau near the Rio Blanco County line.