- Name also: Turkish Wartycabbage, Turkish Rocket, Hill Mustard
- Family: Mustard Family – Brassicaceae (Cruciferae)
- Growing form: Biennial or perennial herb. Strong-rooted.
- Height: 60–100 cm (25–40 in.). Many-branched, stem upper part branching, roughly haired.
- Flower: Corolla regular (actinomorphic), yellow, approx. 1 cm (0.4 in.) wide; petals four, 4–7 mm (0.16–0.28 in.) long. Sepals 4. Stamens 6, of which 2 short and 4 long. Gynoecium fused, a single carpel. Inflorescence abundantly branched, raceme, extending in fruiting stage. Flowers with sweet fragrance.
- Leaves: In basal rosette and alternate on stem, rosette leaves stalked, stem leaves short-stalked–stalkless. Blade lanceolate, hairy, large-toothed, rosette leaves usually pinnately lobed at base.
- Fruit: 1–2-seeded, globose–egg-shaped, flat, with protuberances, hard, not opening, 7–9 mm (0.28–0.36 in.) long silicula. Stalk spreading, 1–2 cm (0.4–0.8 in.) long.
- Habitat: Old barracks, fortresses, beside roads and railways, waste ground, mills, cattle yards, sometimes fields.
- Flowering time: June–July.
Warty cabbage is native to the dry lowlands of the Black Sea steppe, which is a very demanding environment: the soil cracks as it dries, so warty cabbage spends the first year of its life growing a tap root which can reach down up to 2 metres into the ground. This adaptation also allows it to colonise other areas that have rich soil deep down – in its Russian homeland it is a troublesome weed. The species spread to the north in the mid-18th century when the Russian empress sent grain seed to their old enemy Sweden when it was suffering from famine. Unfortunately the grain contained so many warty cabbage seeds that the plant became a real nuisance in central Swedish fields. It then spread to a large part of Europe in 1814 with the Russian soldiers that followed Napoleon’s retreating army. Warty cabbage arrived in Finland with Russian soldiers’ provisions, mainly mixed in with grain and hay to feed Cossacks’ horses.
Warty cabbage can still be found in the areas where Russian soldiers were most active: old barracks and garrison areas are adorned with bright yellow at the beginning of summer when warty cabbage blooms, and the sickly sweet fragrance of the flowers attracts many kinds of nectar-hunting insects. Warty cabbage spreads mainly via its seeds, which can germinate after lying a long time dormant: the finger-thick stem stands rigidly throughout the winter and the seeds spread efficiently across the frozen snow. In the days of Russian rule warty cabbage began to become more common with garrisons in the 1910s, and it is still spreading along highways and byways. Nowadays it grows in many inhabited areas in central and southern parts of Finland, and is casual in places as far north as central Lapland. Farmers were quite worried at the time when warty cabbage began to spread, but Finnish fields are probably too acidic for the species as it has never established a foothold around crops. The largest member of the Mustard family that grows in Finland is thus regarded as more of an ornamental than a weed.