Scientific name: Cirsium arvense (L.) Scop
Common names: Canada thistle, Californian thistle, Canadian thistle, creeping thistle, field thistle, corn thistle, perennial thistle, field thistle
Native To: Europe (Nuzzo 1997)
Date of U.S. Introduction: 1600s (Nuzzo 1997)
Images: Invasive.org and Google
Means of Introduction: Possibly accidental through farm seed shipments
Impact: Crowds out native species (Stachion and Zimdahl 1980); reduces crop and forage yields (Malicki and Berbeciowa 1986)
Current U.S. Distribution:
• Northern Distribution Map (PDF | 240 KB) / Invasive Species Maps
USDA. FS. Northern Research Station.
• National Agricultural Pest Information System – Pest Tracker – Reported Status
• PLANTS Database map (see complete PLANTS Profile for county distribution and native status)
• Early Detection & Distribution Mapping System
U.S. States and U.S. National Parks Where Reported Invasive: Invasive Plant Atlas of the United States map
The roots of first year plants can be eaten raw or cooked. They are nutritious but rather bland, and are best used in a mixture with other vegetables. The stems can be peeled and cooked like asparagus or rhubarb. Leaves – raw or cooked – are edible too. The root has been chewed as a remedy for toothache. A decoction of the roots has been used to treat worms in children. The root is tonic, diuretic, astringent, antiphlogistic (anti-inflammatory) and hepatic.
Hepatic: Having to do with the liver. Pronounced hi-‘pa-tik. From the Latin hepaticus derived from the Greek hepar meaning (not too surprisingly) the liver. The seed fluff is used as a tinder. The seed of all species of thistles yields a good oil by expression. The seed of this species contains about 22% oil and is a great remedy for healthy hear.
( Tinder is easily combustible material used to ignite fires by rudimentary methods. A small fire consisting of tinder is then used to ignite kindling.)