London Rocket

A common species found from hills to plains in our area; very variable in leaf, flower and pedicel size. but rocket like leaves, smaller flowers and fruits on thin ascending pedicels distinguishes it.

The above first record from Nei Mongol is based on Liu 12 (MO).

Annual, (10-)20-60 cm tall, erect, branched, glabrous or sparsely hairy with simple hairs. Basal and lower leaves petiolate, pinnately lobed with a hastate terminal lobe larger than the laterals, 2-6-jugate, very variable in size; cauline leaves similar but only 1-3-jugate. Racemes 50-80(-100)-flowered, up to 30 cm long in fruit with siliquae overtopping young flowers and buds. Flowers c. 3 mm across, yellow; pedicels (5-)10-15 mm long in fruit, filiform, ascending or sub-spreading, rarely spreading. Sepals 2-2.5 mm long. Petals (2.5-) 3-4 mm long, c. 1 mm broad, usually slightly longer than the sepals. Stamens c. 2:3 mm long; anthers c. 0.5 mm long. Siliquae (25-)30-45 mm long, 1 mm broad, linear, often slightly upcurved; valvex submembranous, convex, obscurely to distinctly torulose, faintly 3-veined but the mid-vein distinct, glabrous; style inconspicuous, thickened, with a depressed, sub-bilobed stigma; septum hyaline; seeds 20-40 in each locule, c. 1 mm long, oblong-ellipsoid, yellowish-brown.

Herbs annual, (10-)20-60(-75) cm tall. Stems erect, branched below and above, glabrous or sparsely pubescent at least basally. Basal leaves not rosulate; petiole (0.5-)1-4.5(-6) cm; leaf blade oblanceolate or oblong in outline, runcinate-pinnatisect, (1.5-)3-12(-15) × (0.5-)1-6(-9) cm; lateral lobes (1 or)2-6(-8) on each side of midvein, smaller than terminal, oblong or lanceolate, entire, dentate, or lobed. Uppermost cauline leaves smaller than basal, entire or 1-3-lobed. Fruiting pedicels divaricate or ascending, slender, much narrower than fruit, (5-)7-12(-20) mm. Sepals oblong, erect, 2-2.5 × 1-1.5 mm. Petals yellow, oblong-oblanceolate, 2.5-3.5(-4) × 1-1.5 mm; claw subequaling sepals. Filaments yellowish, erect, 2.5-4 mm; anthers oblong, 0.5-0.9 mm. Ovules 40-90 per ovary. Fruit narrowly linear, slender, terete, (2.5-)3-4(-5) cm × 0.9-1.1 mm, straight or slightly curved inward, younger ones overtopping flowers; valves glabrous, slightly torulose; style 0.2-0.5 mm; stigma prominently 2-lobed; septum membranous. Seeds oblong, 0.8-1 × 0.5-0.6 mm, inserted in depressions of septum. Fl. May-Aug, fr. Jun-Sep. 2n = 14.

Nepal, Afghanistan, China, India, Kashmir, Pakistan, tajikistan, Turkemenistan, Uzbekistan, W. Asia, Europe.

Distribution: Europe, most of Asia and N. Africa.

Nei Mongol, Taiwan, Xinjiang [Afghanistan, India, Kashmir, Nepal, Pakistan, Tajikistan, Turkmenistan, Uzbekistan; W Asia, Europe].

100 - 1700 m.

Fl. Per.: March-May.

Rocky slopes, orchards, roadsides, fields, pastures, waste grounds, prairies, disturbed sites; near sea level to 1700 m.

Arabis charbonnelii H. Léveillé.