Field Guide to Plants Poisonous to Livestock: Western U.S.
Common names: Orange sneezeweed, Owlclaws
Region: W U.S.
Habitat: Mountain meadows, moist places
Toxic season: Year-round, esp. late summer and fall
Features: Leafy, stout plant up to 4' tall. Leaves alternate, up to 1" long, lance-shaped, becoming narrower near stem, angled upward, margins primarily toothless. Flower heads yellow-orange, 2-3" wide with drooping rays 1" long, each with 3 teeth at tips; same-color center disk. Fruits seed-like, covered with tan hairs and sharp pointed scales.
Poison type: Sesquiterpene lactone
Signs/effects: Liver, kidney, lung damage possible, plus gastrointestinal irritation. Depression, appetite loss, weak irregular pulse, weakness, stiffness, nasal discharge, bloat, "spewing sickness" including vomiting, foaming at the mouth, coughing, green nasal discharge, diarrhea, photosensitization. Death may occur rapidly, 4 to 24 hours of ingestion, or over a longer period in chronic cases.
Treatment: Activated charcoal if ingestion recent. Provide supportive care, watch for aspiration pneumonia.
Comments: All parts toxic. Sheep, goats may be most susceptible, followed by cattle. Llamas and alpacas may also be affected. Low palatability, but is grazed when other forage sparse. Two pounds of fresh leaves per day for 10 days may be adequate to poison a sheep. Other members of the genus may also be toxic.
© Copyright 1998 by Shirley A. Weathers