Scientific Name: Lactuca Canadensis

Common Name: Canada lettuce

Synonyms: Lactuca canadensis var. integrifolia, Lactuca canadensis var. latifolia, Lactuca canadensis var. longifolia, Lactuca canadensis var. obovata, Lactuca canadensis var. typica, Lactuca sagittifolia, Lactuca steelei

Habit: Canada lettuce is non-woody and grows upright from 3-8ft tall. It typically does not have branches but a hairless green (sometimes red) main stem.

Leaves: Its leaves are light/dark green; some purple can be seen on the edges and arranged alternately. The leaves can be 10 inches (250mm) long and 3 inches wide (75mm). They are oblong/lanceolate. Most leaves have lobes; the largest leaves have large lobes, while the smaller leaves have smaller lobes. The leaves may have hairs along the bottom of the vein.

Identifying Characteristics: Latuca canadensis is similar to prickly lettuce (<a href='../../weedimg/555'>Lactuca serriola</a>); however, Canada is more green, while prickly has a blue tint. Canada lettuce also has achenes that are longer than the thread-beaks.

Flower Seed Head: The flowers are typically yellow/reddish-orange and 8-25mm in diameter. The flowers typically bloom in late summer/fall.

Seed Fruit: The seeds are achenes (small, one-seeded dry fruit, that don't split) with white hair and black spots. They are attached by beaks (thread-like).

Where Found: Can be found in woods, pastures, roadsides, gravel lots, landscape beds, and crop fields.

  • Life cycle: biennial

  • Milky sap: Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Asteraceae

  • Leaf arrangement: alternate

  • Leaf shape: lance; oval

  • Ochrea: Not Present

  • Leaf margin: lobed; serrated

  • Stem hairs: no hairs

  • Flower color: orange; red; yellow

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs; no hairs

  • Flower diameter: nickle; quarter; dime; pencil

  • Flower symmetry: radial symetery

  • Root structure: taproot

  • Leaf stalk: none