大蒜芥 da suan jie

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.

Roadsides, fields, pastures, waste grounds, disturbed sites, grasslands; sea level to 2500 m. Liaoning, Xinjiang, Xizang [Afghanistan, India, Japan, Kashmir, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Turkmenistan, Uzbekistan; native to Europe and W Asia; naturalized worldwide].

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.