Yellow star thistle (Centaurea solstitialis) is an annual weed found predominately in the western United States. Yellow star thistle is a grayish-green colored plant which has multiple rigid stems extending in all directions from its base. It produces bright, star-like yellow flowers that are shielded by long, spiny bracts. Yellow star thistle has a deep taproot, which allows it to thrive during dry, hot summers and drought periods. Yellow star thistle begins to experience significant early growth in late May to early June and flowers early to mid-July. It can often go unnoticed until the plant begins to flower, but once the bright yellow, dandelion like flowers bloom, the plant is easily detected.
Toxic components
Yellow star thistle contains eight sesquiterpene lactones that consist of: solstitialin A, repin, subluteolide, acroptilin, janerin, cynaropicrin, lactones solstitiolide and episolstitiolide. These toxins have a cumulative effect on ruminants, meaning they accumulate in the body over time and can lead to irreversible neurological damage. Yellow star thistle causes the same clinical signs as Russian knapweed (Centaurea repens), but is considered more toxic.
- Anxiousness
- Impaired Ability To Eat Or Drink
- Sudden Onset Of Involuntary Facial Movements
- Continuous Chewing Movements
- Jaw Held Open Or Tightly Closed
- Dehydration
- Severe Weight Loss
- Depression
- Submerging Head Into Deep Water To Drink
- Yawning
MECHANICAL: Mow at early flowering.
BIOLOGICAL: Three seed head weevils, two seed head flies, yellow thistle bud weevil. Graze after bolting prior to spine formation. Several years needed to deplete seed reservoir.
CHEMICAL:
References- USDA Centaurea solstitialis Fire Effects Information System. 2018.
- Swearingen, J., C. Bargeron Invasive Plant Atlas of the United States University of Georgia Center for Invasive Species and Ecosystem Health. 2016.
- Early Detection & Distribution Mapping System Available online at http://www.eddmaps.org/; last accessed August 5, 2014. The University of Georgia - Center for Invasive Species and Ecosystem Health.. 2014.
- United States Department of Agriculture (USDA) Plants Poisonous to Livestock in the Western States Agriculture Information Bulletin Number 415. 2011.
- DiTomaso J, Kyser G, Pitcairn M California Invasive Plant Council Yellow Starthistle Management Guide. 2006.
- Moret S, Populin T, Conte LS, Cosens G. HPLC determination of free nitrogenous compounds of Centaurea solstitialis (Asteraceae), the cause of equine nigropallidal encephalomalacia. Toxicon. 2005.
- Roy DN, Peyton DH, Spencer PS. Isolation and identification of two potent neurotoxins, aspartic acid and glutamic acid, from yellow star thistle (Centaurea solstitialis) Natural Toxins. 1995.
