Page authors: David Giblin, Don Knoke
Isatis tinctoria
Dyer's woad
WTU specimens
Other herbaria

Distribution: Known only from scattered locations in central Washington; British Columbia south to California, east to the Rocky Mountains; also occurring in parts of central and eastern North America.

Habitat: Disturbed dry ground, pastures, and roadsides, where often escaped from cultivation.

Flowers: April-June

Origin: Introduced from Eurasia

Conservation Status: Not of concern

Description:
General:

Biennial or perennial, the one main stem 4-12 dm. tall, simple below but branched above, glabrous and glaucous.

Leaves:

Basal leaves several in a rosette, long-petiolate, oblanceolate, up to 18 cm. long, with a few, soft, unbranched hairs; cauline leaves lanceolate to elliptic, sessile and auriculate, entire and glabrous.

Flowers:

Racemes compound, numerous, bractless; pedicles slender, enlarged below the flower, reflexed, shorter than the fruits; sepals 4, not saccate at base; petals 4, yellow, spatulate, 3.5 mm. long; style lacking, the stigma sessile, bi-lobed.

Fruits:

Fruits oblong-oblanceolate, 12-18 mm. long, 5-7 mm. broad.

Accepted Name:
Isatis tinctoria L.
Publication: Sp. Pl. 2: 670. 1753. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Isatis tinctoria in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Isatis tinctoria checklist entry.

E-Flora BC: Isatis tinctoria atlas page.

CalPhotos: Isatis tinctoria photos.

USDA Plants: Isatis tinctoria information.

8 photographs:
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