Brassica nigra (L.) W.D.J.Koch

Annual herb with lax rosette. Stems erect, glabrous above, bristly below, ribbed, 0.6–1–(2) m tall. Lvs green, petiolate, sparsely bristly. Lower lvs lyrate-pinnatifid, to 16 cm long; margins dentate; terminal lobe large, 3-lobed to ovate; lateral lobes subacute, in 1–2 pairs. Upper stem lvs not lobed, becoming entire, lanceolate, 3–5 × 0.5–1 cm. Racemes to 40 cm long; buds overtopping or level with open fls. Sepals narrow-oblong, 3–4 × c. 1 mm. Petals bright yellow, 7–8 × 2–3 mm. All stamens erect. Silique quadrangular, glabrous, oblong, appressed to rachis, somewhat constricted between seeds, (6)–12–25 × 2 mm; gynophore 0; valves strongly keeled, with prominent median and weak lateral veins; beak slender, seedless, (1.5)–2–4 mm long. Seeds red-brown, c. 1 mm diam.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

Flowering: Dec.–May.; Fruiting: Dec.–May.