Scientific Name: Cirsium arvense
Common Name: Canada thistle
Family Name: Asteraceae
Origin: Central / west Asia, Europe
Hardiness Zone: Zone 4: (-34 to -29 °C)
Plant Type: Herbaceous perennial, Invasive plant, Weed (horticultural)
Mature Size: 0.7 - 1.3m x 1.0 - 1.5m (height x width)
Habit: Stiffly upright
Form: Oval - vertical
Texture: Medium
Landscape Uses: Attract birds, Wildlife food
Exposure: Full sun
Soil or Media: Rocky or gravelly or dry
Leaves: Simple, Lobed, Alternate, Prickly, Pubescent, Oblong, Pinnately lobed, Pectinate, Spinose
Flowers: Head (capitulum), Violet, Purple, Pink, Jun-Jul-Aug
Fruit: Achene, Brown, Aug-Sep
Key ID Features:
Perennial weed with rhizomes and nearby plantlets; stem leaves alternate, most oblong, 10-18cm long x 3-7cm wide, irregularly pinnately lobed with spines on margins, white pubescence on under sides; stems are spineless; heads unisexual, male florets 12-14mm long, female florets 22-26mm long, pink to purple, tubular; achenes 2.5-4mm long. <a href ='https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Cirsium%20arvense' target='_blank'>E-FloraBC</a>