Isatis tinctoria

Linnaeus

Sp. Pl. 2: 670. 1753.

Common names: Dyers woad
WeedyIntroducedIllustrated
Treatment appears in FNA Volume 7. Treatment on page 568. Mentioned on page 193.

Plants glaucous, usually glabrous, sometimes pubescent proximally. Stems (3–) 4–10 (–15) dm. Basal leaves: petiole 0.5–5.5 cm; blade oblong or oblanceolate, (2.5–) 5–15 (–20) cm × (5–) 15–35 (–50) mm, base attenuate, margins entire, repand, or dentate, apex obtuse. Cauline leaves: blade usually oblong or lanceolate, rarely linear-oblong, base sagittate or auriculate, apex acute. Fruiting pedicels 5–10 mm. Flowers: sepals 1.5–2.8 × 1–1.5 mm, glabrous; petals 2.5–4 × 0.9–1.5 mm, base attenuate; filaments 1–2.5 mm; anthers 0.5–0.7 mm. Fruits black or dark-brown, often broader distal to middle, (0.9–) 1.1–2 (–2.7) cm × 3–6 (–10) mm, base cuneate, margins sometimes slightly constricted, apex usually subacute or rounded, rarely subemarginate; locule with distinct midvein, lateral-veins inconspicuous, 3–6 (–10) mm; apical wing 3.5–5 (–7) mm wide. Seeds light-brown, 2.3–3.5 (–4.5) × 0.8–1 mm. 2n = 14, 28.


Phenology: Flowering Apr–Jun.
Habitat: Roadsides, fields, pastures, sagebrush hillsides, prairies, railroad embankments, waste places
Elevation: 300-2200 m

Distribution

V7 918-distribution-map.gif

Introduced; B.C., Nfld. and Labr. (Nfld.), Ont., Que., Calif., Idaho, Ill., Mo., Mont., Nev., N.Mex., N.Y., Oreg., Utah, Va., Wash., W.Va., Wyo., Europe, c, sw Asia, n Africa, also in South America (Chile), also in South America (Peru)

Discussion

Isatis tinctoria has been cultivated since ancient times as a source of a blue dye (woad) obtained by fermenting the ground leaves and proximal portions of the plant.

Selected References

None.

Lower Taxa

None.

"elongated" is not a number."thick" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Isatis tinctoria"
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
rounded +, subacute +, acute +  and obtuse +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Ihsan A. Al-Shehbaz +
Linnaeus +
cuneate +, attenuate +, auriculate +  and sagittate +
appendaged +  and unappendaged +
15 cm150 mm <br />0.15 m <br /> (20 cm200 mm <br />0.2 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dentate +, repand +  and entire +
linear-oblong;lanceolate;oblong;oblanceolate;oblong +
much smaller +  and reduced +
1.5 cm15 mm <br />0.015 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
well-developed +
not +  and differentiated +
Dyers woad +
emarginate +  and entire +
accumbent +  and incumbent +
B.C. +, Nfld. and Labr. (Nfld.) +, Ont. +, Que. +, Calif. +, Idaho +, Ill. +, Mo. +, Mont. +, Nev. +, N.Mex. +, N.Y. +, Oreg. +, Utah +, Va. +, Wash. +, W.Va. +, Wyo. +, Europe +, c +, sw Asia +, n Africa +, also in South America (Chile) +  and also in South America (Peru) +
300-2200 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
actinomorphic +
1-seeded +  and sessile +
2 cm20 mm <br />0.02 m <br /> (2.7 cm27 mm <br />0.027 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
dark-brown +  and black +
indehiscent +
1.1 cm11 mm <br />0.011 m <br /> (2 cm20 mm <br />0.02 m <br />) +
distal +  and middle +
pubescent +  and glabrous +
angustiseptate +, obovate +, elliptic +, oblanceolate +  and oblong +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Roadsides, fields, pastures, sagebrush hillsides, prairies, railroad embankments, waste places +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
dentate;repand;dentate;repand;entire +
constricted +
median +  and lateral +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
2.5mm;4mm +
rudimentary +
oblanceolate +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
Flowering Apr–Jun. +
trinucleate +  and 3(-11)-colpate +
slender +
flattened +  and rounded +
mucilaginous +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
not +  and mucilaginous +
light-brown +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
saccate +  and not saccate +
persistent +  and caducous +
distinct +
ascending +  and erect +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
perforated +  and complete +
reduced +
1-seeded +  and sessile +
pubescent +  and glabrous +
angustiseptate +, obovate +, elliptic +, oblanceolate +  and oblong +
1-seeded +  and sessile +
pubescent +  and glabrous +
angustiseptate +, obovate +, elliptic +, oblanceolate +  and oblong +
Weedy +, Introduced +  and Illustrated +
tetradynamous +
branched +  and unbranched +
procumbent +  and decumbent +
2-lobed +, entire +, conical +  and capitate +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
Cruciferae +
Isatis tinctoria +
species +
scale-like +  and forked +
coiled +, 1-7-veined +  and veined +
pubescent +  and glabrous +
anastomosing +
pubescent +  and glabrous +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
aquatics +  and terrestrial +
pubescent +, glabrous +  and glaucous +