Scientific NameLactuca canadensis
Synonyms (former Scientific Names):
Lactuca canadensis var. typica
Lactuca canadensis var. longifolia
Lactuca canadensis var. obovata
Lactuca canadensis var. latifolia
Lactuca canadensis var. integrifolia
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.
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.
Latuca canadensis is similar to prickly lettuce (Lactuca serriola); 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.
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).
Can be found in woods, pastures, roadsides, gravel lots, landscape beds, and crop fields.
upright and nonwoody
Thorns or Spines
Approximate Flower Diameter
Dominant Flower Color
Stem Cross Section
round or oval