Page authors: Ben Legler, David Giblin
Brassica nigra
black mustard

Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout much of North America.

Habitat: Distrubed areas such as roadsides, fields, and waste lots.

Flowers: May-August

Origin: Introduced from Eurasia

Growth Duration: Annual

Conservation Status: Not of concern


Tall annual herb; stems 0.4-1.5 meters tall; usually branching; hairy near base.


Alternate; lower leaves pinnately lobed; upper leaves simple.


In bright yellow clusters (racemes) at stem tips; with 4 petals.


Narrow pods (siliques) to 2.5 cm long.

Identification Notes:

Distinguished from other Brassica spp. mostly by fruit characteristics; see technical keys.

Accepted Name:
Brassica nigra (L.) W.D.J. Koch
Publication: Deutschl. Fl. ed. 3. 4: 713. 1833.

Synonyms & Misapplications:
Sinapis nigra L.
Additional Resources:

PNW Herbaria: Specimen records of Brassica nigra in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Brassica nigra checklist entry.

E-Flora BC: Brassica nigra atlas page.

CalPhotos: Brassica nigra photos.

USDA Plants: Brassica nigra information.

16 photographs:
Group by