Yellow Star-thistle
Centaurea solstitialis

sen-TORE-ee-a  sol-sti-shee-AY-lis

FAMILY: Asteraceae (Sunflower)

DESCRIPTION: {introduced} This annual plant is the scourge of our area, found along the roadsides and taking over any disturbed sunny pasture. It starts out as a basal rosette and concentrates on developing a very deep tap root. Once most of the spring flowers and grasses are dying back, the Yellow Star-thistle "bolts", growing up to 4 feet tall using ground water from its deep roots. It then produces a wicked thistle head with a yellow flower head, and many many seeds that are viable for the next five years.

HABITAT: Pastures, roadsides, disturbed grassland or woodlands to 3,600'.

NOTES: Bad Plant! BAD BAD Plant!! Not only are these stiff spine stout enough to puncture my lawn tractor tires, the plant is cumulatively TOXIC to horses.