Lactuca serriola
Prickly lettuce
Photo by Chez Brungraber
Family: Asteraceae · Type: Herb · Not Native
Lactuca serriola (Prickly lettuce) is a non-native California herb in the Asteraceae family, recognized by . Key feature: unique prickly-bristly stems and leaf veins.
Prickly lettuce is a naturalized annual found throughout California in disturbed places at elevations below 2,700 meters. Flowering from May to October, this plant produces pale yellow flowers in small heads 4 to 6 millimeters wide, arranged in open, spreading panicle-like clusters. Growing with tall, erect stems 0.5 to 3 meters high that are notably prickly-bristly, it develops quickly in disturbed environments. Its leaves are oblanceolate to oblong-elliptic, with prickly-bristly margins and bases that clasp the stem, often unlobed or with coarse lobes. The fruit is light to dark brown, 2.5 to 3.5 millimeters long with a thread-like beak and distinctive ribbed surfaces.
Identification and appearance
Key characters: 6 sympatric species. Key feature: unique prickly-bristly stems and leaf veins
Habitat and range
Habitat: Abundant. Disturbed places
Elevation: < 2700 m
Outside California: North America, native to Europe
Bloom period
Lactuca serriola blooms May-Oct.
How to tell it apart
vs Sonchus: Look at seeds - Lactuca seeds have a distinct beak/neck, Sonchus bristles attach directly to seed.; vs Taraxacum: Taraxacum has all basal leaves on leafless stalks, Lactuca has leafy branching stems.; vs Helminthotheca: Helminthotheca has spiny-bristly outer phyllaries and yellow-orange flowers, Lactuca has smooth phyllaries.; vs Brassica: Brassica has 4-petaled cruciform flowers and long seed pods, not composite heads with bristly seeds.; vs Stephanomeria: Stephanomeria has only 3-9 flowers per small head, Lactuca has many more flowers per head.
Frequently asked questions
Is Lactuca serriola native to California?
No. Lactuca serriola is not native to California (recorded as not native).
When does Lactuca serriola bloom?
Lactuca serriola blooms May-Oct.
What plant family does Lactuca serriola belong to?
Lactuca serriola is in the Asteraceae family, genus Lactuca.
What habitat does Lactuca serriola grow in?
Lactuca serriola grows in Abundant. Disturbed places.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.