Abstract
•Toxic larkspurs (Delphinium spp.) in western North America are abundant native plants on foothill and mountain rangelands.•Previous analysis for toxic alkaloids in waxy larkspur indicated that this plant was highly toxic. However, no information on cattle grazing of waxy larkspur was available.•We conducted a small grazing study in spring 2012 near Challis, Idaho, and found that cattle consumed sufficient quantities of waxy larkspur to become poisoned. The risk of death losses by cattle is particularly high because of the very high concentrations of alkaloids in young waxy larkspur plants.