Photo/Illustrations Credit: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 3: 560
Yellow Starthistle can form solid stands, displacing other vegetation, reducing forage for livestock and wildlife and increasing erosion. It is poisonous to horses and the spines can injure other grazers. Yellow Starthistle can be identified by winged stems, a flower with bright yellow petals atop a distinctive spiny bud, and cottony pubescence covering the stem and leaves.
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Sulfur Cinquefoil spreads rapidly, is often misidentified as one of the native cinquefoils, and is very difficult to control. It can be identified by pale yellow flowers and leaves that grow upright against the stem and overlap one another.
Whitetop invades moderately moist, sunny sites in rangelands and pastures. It can be distinguished from other white flowered mustards by its smooth (not ribbed) stems, puffed seedpods and extensive root system.
Rush Skeletonweed can be found scattered within the Grande Ronde, Snake and Joseph Creek Watersheds. It can be identified by 7 to 15 bright yellow petals with distinct teeth at the ends, branched stems with a few very small leaves, and coarse reddish hairs near the stem’s base.
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