Page author: David Giblin
Chorispora tenella
crossflower, blue mustard

Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout much of western and central North America.

Habitat: Shrub-steppe habitat, both degraded and intact; disturbed areas, roadsides, and pastures.

Flowers: March-June

Origin: Introduced from sw Asia

Conservation Status: Not of concern


Annual with stalked glands and simple hairs, the stem 1-5 dm. tall, usually with several basal, decumbent branches.


Leaves alternate, elliptic-oblong to lanceolate or oblanceolate, all but the uppermost petiolate, the blade 3-8 cm. long, deeply wavy-toothed.


Inflorescence of elongate racemes, the lower flowers from the axils of slightly reduced leaves, the main part of the raceme bractless; calyx narrowly tubular, 6-8 mm. long, the lateral sepals somewhat saccate at the base; petals 4, pale magenta, the narrow claw slightly exceeding the sepals, the spreading, oblong blades 5 mm. long; stamens 6; style none.


Siliques 3.5-4.5 cm. long, terete, spreading, curved, and ascending, strongly 1-nerved, constricted between the seeds and eventually breaking at the constrictions; upper portion of the silique sterile and forming a sharp beak 7-20 mm. long.

Accepted Name:
Chorispora tenella (Pall.) DC.
Publication: Syst. Nat. 2: 435. 1821. 1821.

Synonyms & Misapplications:
Chorisporum tenellum (Pall.) R. Br.
Raphanus tenellus Pall.
Additional Resources:

PNW Herbaria: Specimen records of Chorispora tenella in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Chorispora tenella checklist entry.

E-Flora BC: Chorispora tenella atlas page.

CalPhotos: Chorispora tenella photos.

USDA Plants: Chorispora tenella information.

44 photographs:
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