Isatis

Linnaeus

Sp. Pl. 2: 670. 1753.

,

Gen. Pl. ed. 5, 301. 1754.

Common names: Woad
Etymology: Greek isatis, name used for a dye plant, most likely woad
Treatment appears in FNA Volume 7. Treatment on page 567. Mentioned on page 230, 239, 244.

Biennials [annuals, perennials]; not scapose; (often glaucous), glabrous or pubescent. Stems erect, often unbranched basally, paniculately branched distally. Leaves basal and cauline; petiolate or sessile; basal rosulate [or not rosulate], petiolate [rarely sessile], blade margins entire, repand, or dentate [rarely pinnately lobed]; cauline blade (base auriculate, sagittate, [or amplexicaul, rarely attenuate]), margins entire [dentate]. Racemes (corymbose, in panicles, several-flowered), considerably elongated in fruit. Fruiting pedicels reflexed, slender, (filiform, often thickened and clavate apically). Flowers: sepals erect or ascending, oblong [ovate]; petals oblanceolate [obovate, spatulate, or oblong], (equal to or longer than sepals), claw absent, (apex obtuse [subemarginate]); stamens slightly tetradynamous; filaments not dilated basally; anthers oblong [ovate], (apex obtuse or apiculate); nectar glands (6) confluent, or (4) lateral and median. Fruits siliques or silicles (samaroid), sessile, oblong, oblanceolate, elliptic, or obovate [ovate, cordate, spatulate, orbicular], 1- (or 2-)seeded, smooth, strongly angustiseptate, (prominently winged all around or distally; seed-bearing locule papery or corky, distinctly or obscurely 1–3-veined, sometimes keeled or shortly winged), glabrous or pubescent; valves and replum united; septum absent; ovules 1 (or 2) per ovary, (subapical); stigma capitate. Seeds plump, not winged, narrowly oblong; seed coat (smooth), not mucilaginous when wetted; cotyledons incumbent or accumbent.

Distribution

Introduced; Europe, c, sw Asia, n Africa, introduced also in South America (Chile, Peru).

Discussion

Species 50 (1 in the flora).

Selected References

None.

Lower Taxa

... more about "Isatis"
Ihsan A. Al-Shehbaz +
Linnaeus +
Europe +, c +, sw Asia +, n Africa +, introduced also in South America - Chile +  and Peru. +
Greek isatis, name used for a dye plant, most likely woad +
Sp. Pl. +  and Gen. Pl. ed. +
1753 +  and 1754 +
Cruciferae +
Brassicaceae tribe Isatideae +