Brassica rapa
Turnip, field mustard, Field Mustard
(c) Mark Wagner, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Not Native
Conservation status: Cal-IPC Yes
Brassica rapa (Turnip) is a non-native California herb in the Brassicaceae family, recognized by flowers overtopping buds, plus clasping leaf bases.
Turnip is a naturalized annual plant found in the California Floristic Province and southeastern deserts in disturbed areas at elevations below 1,500 meters. Flowering from January to May, this plant produces yellow flowers about 6 to 11 millimeters long with distinctive petals. Growing 30 to 100 centimeters tall with erect stems that are simple or branched, it develops a robust and spreading habit. Its leaves are uniquely structured with basal leaves pinnately lobed and having 2 to 4 pairs of lateral lobes, with a wavy-dentate terminal lobe that clasps the stem. The plant produces elongated fruits 3 to 8 centimeters long that ascend or spread slightly above the foliage.
Identification and appearance
Key characters: 6 sympatric species; key feature is flowers overtopping buds, plus clasping leaf bases
Habitat and range
Habitat: Disturbed areas
Elevation: < 1500 m
California counties: El Dorado, Los Angeles, Marin, Orange, Riverside, Sacramento, San Bernardino, San Diego, San Luis Obispo, Santa Clara, Solano, Sonoma, Ventura, Alameda, Contra Costa, Lake, San Francisco, San Joaquin, Santa Barbara, Humboldt, San Mateo, Monterey, Imperial, Placer, Yolo, Sutter, Amador, Colusa, Nevada, Alpine, Butte, Sierra, Madera, Santa Cruz, Napa, Plumas, Yuba, Del Norte, Mendocino, Mono, Siskiyou, Calaveras, Tulare, Kern, Tehama, Inyo, Trinity, San Benito, Stanislaus, Tuolumne
Outside California: widespread North America, native to Europe
Bloom period
Brassica rapa blooms Jan-May.
Conservation status
Cal-IPC Yes
How to tell it apart
vs Hirschfeldia: Brassica pods angle outward with faint veining; Hirschfeldia pods press tight against the stem with prominent ribs.; vs Sisymbrium: Brassica has large showy flowers with petals 8-30mm; Sisymbrium has smaller, less conspicuous flowers.; vs Lactuca: Brassica has four-petaled yellow flowers and seed pods; Lactuca has ray flowers like a dandelion and milky sap.; vs Crambe: Brassica pods split open to release many seeds; Crambe produces single-seeded round fruits that don't split.
Frequently asked questions
Is Brassica rapa native to California?
No. Brassica rapa is not native to California (recorded as not native).
When does Brassica rapa bloom?
Brassica rapa blooms Jan-May.
Where in California does Brassica rapa grow?
Brassica rapa occurs in El Dorado, Los Angeles, Marin, Orange, Riverside, Sacramento, San Bernardino, San Diego and other counties, at elevations of < 1500 m.
What plant family does Brassica rapa belong to?
Brassica rapa is in the Brassicaceae family, genus Brassica.
Is Brassica rapa invasive in California?
Brassica rapa is listed by Cal-IPC with an invasiveness rating of Yes.
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.