Charlock Mustard

‘Charlock or wild mustard’ is often found as weed near cultivation, especially in the North and Western areas of W. Pakistan. It is a very variable species and do not cross with any Brassica species. Its green leaves and fruits are edible; fatty oil, obtained from seeds, is used in soap making and also used for food after hydrogenation.

Annual, 20-60 cm tall, erect, branched, usually hispid with spreading simple hairs. Lower leaves usually lyrate-pinnate, stalked, 1-3-jugate, up to 20 cm long, ± hispid; terminal lobe large, ovate, coarsely toothed; upper leaves oblong¬obovate or lanceolate, acute, dentate. Racemes 20-40 (-60)-flowered, corymbose, up to 30 cm long in fruit. Flowers c. 10 mm across, yellow; pedicel 3-5 mm long, hardly increasing but thickened in fruit, ± spreading or ascending. Sepals 4-6 (-7) mm long, 1-1.5 (-2) mm broad, yellowish, subspreading, usually glabrous. Petals 7-12 mm long, 3.5-5 mm broad, obovate, clawed. Stamens 4-5 : 6-7 mm long. Siliquae 25-45 mm long, 2.5-4 mm broad (including beak about 1/3 of the entire length of fruit, and 1-2-seeded), subcylindrical, torulose spreading, often glabrous ; valves 3-5-parallel veined; septum submembranous; seeds 3-7 in each locule (rarely more), c. 1.5 mm in diam., brown to almost black, finely alveolate.

Herbs (5-)20-100(-210) cm, retrorsely or spreading hirsute or hispid, rarely glabrous. Stems erect, often branched above. Petiole of basal and lower cauline leaves 1-4(-7) cm; leaf blade oblong, ovate, or lanceolate in outline, lyrate, pinnatifid, or undivided and dentate, (3-)4-18(-25) × 1.5-5(-7) cm; terminal lobe broadly ovate, obovate, to elliptic, margin dentate; lateral lobes 1-4 on each side of midvein, oblong, ovate, or lanceolate, smaller than terminal one, margin dentate. Upper cauline leaves shortly petiolate; leaf blade ovate or lanceolate, often undivided, margin dentate or subentire, apex acute. Fruiting pedicels ascending or suberect, stout, (2-)3-7(-15) mm. Sepals yellow or green, narrowly oblong, (4.5-)5-6(-7) × 1-1.8 mm, spreading or reflexed. Petals bright or pale yellow, obovate, (0.8-)0.9-1.2(-1.7) cm × (3-)4-6(-7.5) mm. Filaments (3-)4-6 mm; anthers oblong, 1.2-1.5 mm. Fruit linear, (1.5-)2-4.5(-5.7) cm × (1.5-)2.5-3.5(-4) mm; valvular segment (0.6-)1.2-3.5(-4.3) cm, (2-)4-8(-12)-seeded in each locule, 3-5(-7)-veined, torulose, terete, glabrous or pubescent with 1 kind of trichome; terminal segment conical or subulate, terete, (0.7-)1-1.6 cm, straight or curved upward, seedless or 1- or 2-seeded. Seeds blackish to dark brown, globose, (1-)1.5-2 mm in diam., finely reticulate. Fl. and fr. May-Sep. 2n = 18*.

Distribution: Europe, N. Africa, S.W. Asia; widely introduced elsewhere. Centre of origin: Mediterranean region.

Xinjiang [Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; N Africa, SW Asia, Europe; naturalized elsewhere].

Fl. Per.: April-June.

Roadsides, waste places, fields, pastures; 400-1800 m.

Brassica arvensis (Linnaeus) Rabenhorst; B. kaber (de Candolle) L. C. Wheeler; B. sinapistrum Boissier; B. xinjiangensis Y. C. Lan & T. Y. Cheo; Sinapis kaber de Candolle.