Weeds
	Weed Regulations
	Preventing and Controlling Weeds
	Alberta Weed Control Act Information
	Weed Designation Chart
	Blueweed
	Canada Thistle
	Common Tansy
	Diffuse Knapweed
	Leafy Spurge
	Nodding Thistle
	Purple Loosestrife
	Scentless Chamomile
	Spotted Knapweed
	Toadflax

Canada Thistle

Description

Name: Canada thistle (Cirsium Arvense)
Classification: Noxious
Recognizable features:

• Stem upright, branching near the top, hollow
• Leaves alternate, slightly clasping the stem, variable, from a smooth margin with no spines to irregularly lobed with sharp spines
• Flowers small white to purple flowers clustered into a head to resembling a single flower, male (round) and a female (flask or urn shaped) flowers found on separate plants, positioned at the ends of branches
• General Perennial that spreads by seed and creeping roots. Feathery hairs (pappus) attatched to seeds to aid in short distance dispersal.