Scientific Name: Lactuca serriola

Common Name: prickly lettuce

Other Common Names: wild lettuce, China lettuce

Synonyms: Lactuca scariola

Habit: A summer or winter annual, or a biennial that produces erect stems (30 cm to 1.5 m in height) from a basal rosette of leaves. The leaf margin has fine prickles, and the midrib (lower leaf surface) is lined with conspicuous prickles. Reproduction is by seed.

Leaves: Seedling: Cotyledons are rounded, tapering to the base, 7-8 mm long. Pale green leaves develop into a basal rosette. Young leaves are broadly club-shaped to egg-shaped, widest at the apex with distinctly toothed or spiny, wavy or slightly lobed margins. Stiff prickles are present on prominent midrib of lower leaf surface. Mature Plant: Leaves are alternate (5-25 cm long), oblong to lanceolate, stiff and coarse, non-lobed or more often lobed with rounded sinuses. The leaf bases clasp the stem with ear-like lobes. The upper leaf surface is smooth; prickles are present on the leaf margin and on the midrib of the lower surface. Leaves often turn on edge and orient vertically toward the sun. Basal leaves are larger than upper leaves.

Identifying Characteristics: Leaves, roots and stems exude a milky juice when injured. Prominent midrib on under side of leaf has stiff prickles.

Flower Seed Head: Flowering stems are erect and tall (up to 2 m). The main stalk of flowering stems is hollow. The panicle type seedhead branches widely. Numerous small yellow flowers (less than 1/2 inch) are produced on the top portion of erect stalks. Flowers later turn white due to pappus on seed that allow for wind dispersal.

Seed Fruit: Nutlets are brown, oblong, and 3 to 3.3 mm long. Nutlets have five ribs on each face and a slender stalk (3 to 5 mm long) topped with white pappus.

Where Found: Prickly lettuce is common in disturbed sites, gravel driveways, turf, and ornamental beds.

  • Life cycle: winter annual

  • Milky sap: Present

  • Plant type: Herb

  • Thorns: Present

  • Plant family: Asteraceae

  • Leaf arrangement: rosette

  • Leaf shape: spatulate

  • Ochrea: Not Present

  • Leaf margin: serrated; lobed

  • Stem hairs: has hairs

  • Flower color: yellow; white

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs

  • Flower symmetry: radial symetery

  • Flower diameter: pencil; dime; nickle

  • Root structure: taproot

  • Leaf stalk: none