Common Burdock

Arctium minus

Common Name: Common Burdock
Scientific Name: Arctium minus
Family: Asteraceae
Growth Form: Herb
Native Range: Europe
Invasive Range: The United States
Introduction: English and French settlers brought common burdock to America in the 1600s.  Over the next 200-300 years it naturalized across the country, reaching Washington State in the 1930s.  Reproduction is by seed.
Description: ·Leaves: Alternate, egg shaped.  Wavy margins.  40cm by 50cm (16in. by 20 in.) Basal leaves heart-shaped, form rosette.  Upper surface smooth, dark, undersurface furry, light. 

·Stem:  Erect, branched, hollow, hairy, grooved or angular.  Close to the ground.

·Flowers:  Purple disk, 1.5-3 cm (0.75-1.5 in.) in diameter.  Outer bracts of the flower form sphere tipped with hooks that behave like Velcro.  Present from July to October. Flower dries to form a burr

·Fruit: Achene is 4-7 mm (0.1-0.25 in.) long, bristles at one end.  Seeds are grey-brown and wedge shaped.
Threats: Common burdock is generally a weed of pastures, fences, and agricultural crops.  The burrs formed when the flower dries can be dangerous to livestock and domestic animals.
Fun Facts: If ingested, Common burdock can cause intestinal hairballs in dogs and may become lodged in the esophagus of poultry. 
Plant in autumn