Sonchus arvensis
Perennial sow thistle
(c) Dmitriy Bochkov, some rights reserved (CC BY), uploaded by Dmitriy Bochkov · licence
Family: Asteraceae · Type: Herb · Not Native
Sonchus arvensis (Perennial sow thistle) is a non-native California herb in the Asteraceae family, recognized by including its own subspecies; distinguished by perennial rhizomatous habit and larger involucres.
Perennial sow thistle is a naturalized perennial herb found in agricultural and disturbed areas across California. Flowering from June to September, this plant produces yellow flowers in daisy-like heads approximately 2 to 3 centimeters wide. Growing with tall stems 40 to 150 centimeters high emerging from long underground rhizomes, it develops both flowering and non-flowering stems. Its leaves are distinctive, with basal leaves 5 to 15 centimeters long that are deeply lobed and short-petioled, while stem leaves have coarse lobes with curled basal clasping segments. The fruit is dark brown, approximately 2.5 to 3 millimeters long with rough ribbed surfaces.
Identification and appearance
Key characters: Co-occurs with 5 species including its own subspecies; distinguished by perennial rhizomatous habit and larger involucres
How to tell it apart
vs Taraxacum: Taraxacum has all basal leaves on leafless stalks, Sonchus has tall leafy branching stems.; vs Lactuca: Check seeds - Sonchus has no beak, Lactuca seeds have distinct neck before bristles.; vs Helminthotheca: Helminthotheca has spiny-bristly outer phyllaries creating a prickly appearance, Sonchus phyllaries are smooth.; vs Cirsium: Cirsium has spiny flower heads and disk flowers only, Sonchus has smooth heads with ray flowers.; vs Senecio: Senecio has yellow disk and ray flowers, Sonchus has only yellow ray flowers.
Frequently asked questions
Is Sonchus arvensis native to California?
No. Sonchus arvensis is not native to California (recorded as not native).
What plant family does Sonchus arvensis belong to?
Sonchus arvensis is in the Asteraceae family, genus Sonchus.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.