Stem
- Stiff, wiry, 1-6 ft. tall and usually branched; wings less than 0.2 in. wide extend down stem
Leaves
- Blue- to gray-green, 1.5-6 in. long and densely covered with fine hairs
- Rosette leaves are oval to strap-like (linear) with deeply lobed edges (margins); stem leaves are alternate, strap-like to oblong with smooth to wavy edges
Flower
- Yellow, located singly at branch tips or axils; base of flower is vase-shaped, 0.5-0.75 in. diameter and covered with cotton-like hairs and stout, straw-colored spines 0.5-1 in. long
Other
- Infests rangeland, pastures, croplands, waste areas and roadsides; known to occur in Carson City, Douglas, Elko, Humboldt, Lander, Lyon, Storey, Washoe, and White Pine counties
- Annual; reproduces by seed
- Causes “chewing disease” in horses by damaging the area of the brain that controls fine motor movements, particularly of the mouth, resulting in starvation or dehydration
Control
- Grazing, mowing, burning, pulling, digging and cultivation can be effective if done prior to seed production
- Several biological control agents are available
- Apply 2,4-D, dicamba, or triclopyr rosette to bolt; glyphosate bolt to flowering; aminocyclopyrachlor, aminopyralid, clopyralid or picloram preemergence to rosette; chlorsulfuron preemergence
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B.
2020,
Nevada Noxious Weed Field Guide – Yellow starthistle,
Extension, University of Nevada, Reno, Field Guide
