Lactuca canadensis
Canada lettuce
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Asteraceae · Type: Herb · Not Native
Lactuca canadensis (Canada lettuce) is a non-native California herb in the Asteraceae family, recognized by . Key feature: distinctive long involucre and black ribbed fruits.
Canada lettuce is a naturalized biennial found in the Klamath Ranges and northern Sierra Nevada in forest and disturbed areas at elevations below 1,400 meters. Flowering from July to October, this plant produces pale yellow to blue flowers in open heads 5 to 10 millimeters wide arranged in large, panicle-like clusters. Growing with erect stems 50 to 250 centimeters tall from a taproot, it develops numerous leaves that range from linear to ovate with toothed or lobed edges. Its leaves vary from wing-petioled at the base to sessile and clasping higher on the stem, with some upper leaves reduced to linear bracts. The fruit is black, elliptic, and 3 to 4 millimeters long with a slender 2 to 3 millimeter beak topped by a white pappus.
Identification and appearance
Key characters: 4 sympatric species. Key feature: distinctive long involucre and black ribbed fruits
Habitat and range
Habitat: Forest, disturbed areas
Elevation: < 1400 m
Outside California: native to central and eastern North America
Bloom period
Lactuca canadensis blooms Jul-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 canadensis native to California?
No. Lactuca canadensis is not native to California (recorded as not native).
When does Lactuca canadensis bloom?
Lactuca canadensis blooms Jul-Oct.
What plant family does Lactuca canadensis belong to?
Lactuca canadensis is in the Asteraceae family, genus Lactuca.
What habitat does Lactuca canadensis grow in?
Lactuca canadensis grows in Forest, disturbed areas.
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.