Yellow Starthistle

Yellow Starthistle

(Centaurea solstitalis)

Information Sheet (PDF)

Colorado List A - Eradication required 

General

• Family: Sunflower (Asteraceae)
• Introduced from South America and Europe

Habitat

• Annual forb
• Found in rights-of way, disturbed sites, and rangeland

Plant

Vegetation

• Leaves ½ inch wide and 2-4 inches long
• Basal leaves dry up as the plant begins to bolt
• Stems are winged
• Short grayish hairs on the leaves and stems
• Plants up to 3 ½   feet tall

Roots

• Taproot to 3 feet long

Flower

• ½ - 3/4 inch wide
• Bracts covered with spines, center spine 
• Color: Yellow
• Season: May to October
• Single at end of stems

Seed

• Up to 100,000 per plant 

Reproduction

• Seed

Control

Biological

• None

Chemical

• View Information Sheet (PDF)

Cultural

• Prevention
• Removal - make sure the entire root is removed. Must be repeated as new plants germinate

Mechanical

• Burning - N/A
• Grazing - N/A - Poisonous to horses
• Mowing - N/A

Use all chemicals according to the manufacturer's label. No specific recommendation or endorsement is made or implied by listing methods or products.