Tall Tumblemustard

Easily distinguished by its narrow, linear lobes of upper leaves, elongated siliquae with equally thickened pedicels.

The above first record from Xizang is based on Chaffanjon 406 (P).

This species is a noxious weed and is usually a host to several viruses of crop plants.

Annual or biennial, 20-60 (-90) cm tall, erect, branched above, ciliately hairy with long, simple hairs, subglabrous above. Basal and lower leaves loosely rosulate, shortly petioled, runcinate-pinnatifid, 6-15 (-20) cm long, 3-8 cm broad; terminal lobe large, ovate, distantly lobulate, toothed to entire; lateral lobes (4-) 6-8 paired, narrowly oblong; upper leaves 5-7-jugate, with linear to filiform lobes. Racemes 15-25-flowered, up to 30 cm long in fruit, lax. Flowers 5-6 mm across, yellowish; pedicels (5-) 8-12 mm long in fruit, thickened, sub-spreading or ascending. Sepals 4-6 mm long. Petals (6-) 9-12 mm long, c. 4 mm broad, rarely much reduced. Stamens c. 5:7 mm long; anthers c. 2 mm long. Siliquae (50-) 80-100 mm long, 1-1.5 mm broad, linear-subcylindrical, slightly terete, usually straight, glabrous; valves somewhat rigid, 3-veined; style 1-2 mm long, thickened with ± bilobed, capitate-coronate stigma; septum submembranous, somewhat thickened between the seeds; seeds 40-60 in each locule, c. 1 mm long, ellipsoid, brown.

Herbs annual, (20-)40-120(-160) cm tall. Stems erect, branched above, sparsely to densely hirsute near base, glabrous or subglabrous above. Basal leaves rosulate; petiole 1-10(-15) cm; leaf blade broadly oblanceolate, oblong or lanceolate in outline, pinnatisect, pinnatifid, or runcinate, (2-)5-20(-35) × (1-)2-8(-10) cm; lateral lobes (3 or)4-6(-8) on each side of midvein, smaller than terminal one, oblong or lanceolate, entire, dentate, or lobed. Uppermost cauline leaves with narrowly linear to filiform lobes. Fruiting pedicels divaricate or rarely ascending, stout, nearly as thick as fruit, (4-)6-10(-13) mm. Sepals oblong, cucullate, ascending or spreading, 4-6 × 1-2 mm. Petals yellow, spatulate, (5-)6-8(-10) × 2.5-4 mm; claw subequaling sepals. Filaments yellowish, erect, 2-6 mm; anthers oblong, 1.5-2.2 mm. Ovules 90-120 per ovary. Fruit narrowly linear, stout, terete, (4.5-)6-9(-12) cm × 1-2 mm, usually straight; valves glabrous, smooth; style subclavate, 0.5-2 mm; stigma prominently 2-lobed; septum slightly thickened. Seeds oblong, 0.8-1 × 0.5-0.6 mm, inserted in depressions of septum. Fl. Apr-Jul, fr. May-Aug. 2n = 14.

Distribution: Europe, C. and S.W. Asia, Afghanistan. Pakistan and Kashmir.

Liaoning, Xinjiang, Xizang [Afghanistan, India, Japan, Kashmir, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Turkmenistan, Uzbekistan; native to Europe and W Asia; naturalized worldwide].

Fl. Per.: April-July.

Roadsides, fields, pastures, waste grounds, disturbed sites, grasslands; sea level to 2500 m.