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Vascular Plants of California
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Isatis tinctoria
WOAD


Higher Taxonomy
Family: Brassicaceae (Cruciferae)View DescriptionDichotomous Key
Common Name: MUSTARD FAMILY
Habit: Annual to shrub; sap pungent, watery. Leaf: generally simple, alternate; generally both basal, cauline; stipules 0. Inflorescence: generally raceme, generally not bracted. Flower: bisexual, generally radial; sepals 4, generally free; petals (0)4, forming a cross, generally white or yellow to purple; stamens generally 6 (2 or 4), 4 long, 2 short (3 pairs of unequal length); ovary 1, superior, generally 2-chambered with septum connecting 2 parietal placentas; style 1, stigma entire or 2-lobed. Fruit: capsule, generally 2-valved, "silique" (length >= 3 × width) or "silicle" (length < 3 × width), dehiscent by 2 valves or indehiscent, cylindric or flat parallel or perpendicular to septum, segmented or not. Seed: 1--many, in 1 or 2 rows per chamber, winged or wingless; embryo strongly curved.
Genera In Family: +- 330 genera, 3780 species: worldwide, especially temperate. Note: Highest diversity in Mediterranean area, mountains of southwestern Asia, adjacent central Asia, western North America; some Brassica species are oil or vegetable crops; Arabidopsis thaliana used in experimental molecular biology; many species are ornamentals, weeds. Aurinia saxatilis (L.) Desvaux in cultivation only. Aubrieta occasional waif in central NCoR, Carrichtera annua (L.) DC. in SCo, Iberis sempervirens L., Iberis umbellata L. in PR, Teesdalia coronopifolia (Bergeret) Thell., Teesdalia nudicaulis (L.) W.T. Aiton in southern NCoRO, CCo. Cardaria, Coronopus moved to Lepidium; Caulostramina to Hesperidanthus; Guillenia to Caulanthus; Heterodraba to Athysanus; California taxa of Lesquerella to Physaria; Malcolmia africana to Strigosella.
eFlora Treatment Author: Ihsan A. Al-Shehbaz, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.
Genus: IsatisView Description 


Habit: [Annual] biennial [perennial herb]; hairs simple or 0. Leaf: rosetted or not, petioled, entire or lobed; cauline sessile, base lobed to clasping. Inflorescence: elongated. Flower: sepals erect to ascending, base not sac-like; petals yellow or cream, not clawed. Fruit: indehiscent, pendent, oblong to oblanceolate or round to ovate, flat perpendicular to septum, unsegmented, winged; style 0, stigma entire. Seed: 1(2), oblong, plump.
Species In Genus: +- 60 species: Eurasia. Etymology: (Greek: plant with dark dye)
eFlora Treatment Author: Ihsan A. Al-Shehbaz
Isatis tinctoria L.
NATURALIZED
Habit: Biennial, glaucous, glabrous or hairy proximally. Stem: (3)4--10(15) dm, branched distally. Leaf: basal (3)6--20(25) cm, oblong to oblanceolate, entire to wavy or dentate; cauline entire. Inflorescence: panicle of racemes. Flower: sepals 1.5--2.8 mm; petals 2.5--4 mm, 0.9--1.5 mm wide, oblanceolate, yellow. Fruit: (0.9)1.1--2(2.7) cm, 3--6(10) mm wide, oblong-oblanceolate to elliptic-obovate; pedicel reflexed, 5--10 mm, club-shaped near tip. Seed: 2.3--3.5(4.5) mm, oblong. Chromosomes: 2n=14,28.
Ecology: Disturbed areas, pastures; Elevation: 100--2200 m. Bioregional Distribution: KR, CaR, n SNH, MP; Distribution Outside California: western and eastern North America, native to Eurasia. Flowering Time: Apr--Jul Note: Once cultivated as source of the blue dye woad.
Jepson eFlora Author: Ihsan A. Al-Shehbaz
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
Noxious Weed listed by CDFA
Weed listed by Cal-IPC

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Botanical illustration including Isatis tinctoria

botanical illustration including Isatis tinctoria

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Citation for this treatment: Ihsan A. Al-Shehbaz 2012, Isatis tinctoria, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=29342, accessed on June 27, 2022.

Citation for the whole project: Jepson Flora Project (eds.) 2022, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on June 27, 2022.

Isatis tinctoria
click for enlargement
© 2021 Steve Matson
Isatis tinctoria
click for enlargement
© 2009 Neal Kramer
Isatis tinctoria
click for enlargement
© 2009 Neal Kramer
Isatis tinctoria
click for enlargement
© 2021 Steve Matson
Isatis tinctoria
click for enlargement
© 2021 Steve Matson
Isatis tinctoria
click for enlargement
© 2021 Steve Matson

More photos of Isatis tinctoria in CalPhotos



Geographic subdivisions for Isatis tinctoria:
KR, CaR, n SNH, MP
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).





 

Data provided by the participants of the  Consortium of California Herbaria.
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All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).