Fergus County Weed Department

Yellow Starthistle

The annual, yellow starthistle, appears as a basal rosette in the early spring. The leaves of the rosette are deeply lobed with a pointed tip, similar to a dandelion rosette. The rigid stems vary from 1 to 5 feet in height depending on environmental conditions. Stem leaves are vertical, flat extensions along the stem (wings) and are covered with cottony hairs which persist through the winter. Flower heads are yellow and singly located at the ends of branches. Sharp, straw-colored spines up to 3/4 inch long radiate from the bracts in a star pattern. Seeds are of two types. They can be dark-colored without bristles or light-colored with a tuft of white bristles at one end. After seed dispersal a hairy tuft, resembling a cotton-ball, remains on the end of the stem and can persist throughout the winter. Yellow starthistle, a native to Europe, can cause the fatal "chewing disease" if fed to horses.

A Plant by Any Other Name - Another new web page provides access to a specialized segment of the GRIN database devoted to information on noxious weeds.

Pesticide Drift

Pesticide Interactions and Compatibility

Water Effects On Pesticide Performance

Pacific Northwest Insect Management Handbook

Pacific Northwest Weed Management Handbook

Fergus County Weed Control
P O Box 878
Lewistown MT  59457
Phone: 406 535-3970
Fax: 406 535-9220