Brassica juncea
India mustard, India Mustard
(c) WATANABE Hitoshi 渡辺仁, some rights reserved (CC BY) · licence
Family: Brassicaceae · Type: Herb · Not Native
Brassica juncea (India mustard) is a non-native California herb in the Brassicaceae family, recognized by large, wide petals and long fruits with seedless terminal segment.
India mustard is a naturalized annual found in the Great Valley in disturbed areas and fields at elevations below 300 meters. Flowering from May to September, this plant produces yellow flowers with petals 9 to 13 millimeters long and 5 to 7.5 millimeters wide. Growing 2 to 10 decimeters tall with branched stems that become more extensive toward the top, it has a glaucous and glabrous appearance. Its leaves vary from basal (early-deciduous) to cauline, with lateral lobes in 1 to 3 pairs and margins ranging from dentate to lobed. The fruit is spreading to ascending, 3 to 5 centimeters long with a terminal seedless segment 5 to 10 millimeters in length.
Identification and appearance
Key characters: 3 sympatric species; key features are large, wide petals and long fruits with seedless terminal segment
Habitat and range
Habitat: Uncommon. Disturbed areas, fields
Elevation: < 300 m
Outside California: widespread North America, native to Eurasia
Bloom period
Brassica juncea blooms May-Sep.
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 juncea native to California?
No. Brassica juncea is not native to California (recorded as not native).
When does Brassica juncea bloom?
Brassica juncea blooms May-Sep.
What plant family does Brassica juncea belong to?
Brassica juncea is in the Brassicaceae family, genus Brassica.
What habitat does Brassica juncea grow in?
Brassica juncea grows in Uncommon. Disturbed areas, fields.
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.