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Montana Field Guide

Montana Field Guides

Dyer's Woad - Isatis tinctoria

Noxious Weed: Priority 1A
Non-native Species

Global Rank: GNR
State Rank: SNA

Agency Status
MNPS Threat Rank:
C-value: 0

External Links

General Description
Glaucous biennial with a woody, branched taproot. Stems erect, simple, 30–100 cm. Basal leaves petiolate, oblanceolate, 5–18 cm long, entire. Stem leaves lanceolate, sessile, auriculate. Vestiture hirsute with simple hair at the stem base, otherwise glabrous. Inflorescence a branched panicle, each raceme ebracteate. Flowers yellow; petals 2.5–3.5 mm long. Fruit narrowly oblong, blunt-tipped, flattened, 12–18 mm long, lacking a septum; style lacking; seed solitary; pedicel reflexed down, 6–10 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Range Comments
Introduced and naturalized throughout intermountain U.S.; native to Europe (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 88

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)



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Citation for data on this website:
Dyer's Woad — Isatis tinctoria.  Montana Field Guide.  .  Retrieved on , from