Scientific name: Centaurea solstitialis
What Is It?
Yellow starthistle is a plant with thistle-like flowers that grows one to three feet tall. It is found in rangeland, cropland edges, abandoned farmlands and pastures, roadsides, railways, and recreational areas. Yellow starthistle can poison and kill horses.
Is It Here Yet?
Yes. Yellow starthistle is widespread in eastern Washington and found in a few western Washington counties.
Why Should I Care?
Yellow starthistle provides poor and potentially damaging food for cattle and may poison or kill horses that eat large quantities over short periods. Removal of seeds contaminating crops and feed is expensive. Recreational lands are becoming increasingly infested.
How Can We Stop It?
Promote native or desired species to help prevent or limit initial infestations. Clean your vehicles and equipment before moving them from an infested or potentially infested area. Yellow starthistle is listed as a Class B noxious weed in Washington, meaning it is designated for control in certain state regions. Contact the local noxious weed control board for assistance.
What Are Its Characteristics?
- Grows to be 18-36 inches tall and has a deep, woody root.
- Has alternate leaves with bases extending downward, producing a winged effect.
- Stems are dull green and covered with woolly hairs.
- Yellow flowers are thistle-like, with short yellowish spines in a star-like arrangement at the base of the flower head.
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