Skip navigation

Weed Identification

Virginia Tech College of Agriculture and Life Science Virginia Cooperative Extension

prickly lettuce

Family

Asteraceae

Scientific Name

Lactuca serriola
Weed photograph 1
Weed photograph 2
Weed photograph 3
Weed photograph 4
Weed photograph 5
Weed photograph 6
Weed photograph 7

Other Common Names:

China lettuce
wild lettuce

Synonyms (former Scientific Names):

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.

Growth Habit

upright and nonwoody

Thorns or Spines

present

Approximate Flower Diameter

Varies: 
pencil, 
dime, 
nickle

Dominant Flower Color

Varies: 
white, 
yellow

Flower Symmetry

radial symmetery

Leaf Hairs

has hairs

Leaf Shape

spatulate

Leaf Arrangement

rosette

Leaf Margin

Varies: 
lobed, 
serrated

Leaf Structure

simple

Leaf Stalk

none

Stem Hairs

has hairs

Stem Cross Section

round or oval

Milky Sap

present

Root Structure

taproot

Life Cycle

winter annual

Ochrea

not present

Plant Type

Herb