Sinapis arvensis L.

Annual taprooted herb. Stems erect, branching, bearing stiff reflexed hairs especially near base or sometimes glabrous, 50–70 cm tall. Lvs glabrous or with sparse coarse hairs, toothed. Lower lvs lyrate-pinnatifid to lyrate-pinnate, 8–20 × 3–10 cm; terminal leaflet ovate, elliptic or oblong, not lobed, wider than rest of lf; lateral leaflets alternate, ovate to triangular, in (0)–1–3 pairs, the proximal ones sometimes entire. Upper lvs smaller, sessile, not lobed, ovate to oblong to linear. Racemes erect, to 40 cm long, glabrous or with sparse reflexed hairs. Pedicels erect or erecto-patent at fruiting, 3–6–(25) mm long. Sepals ovate to obovate, glabrous, 4–7 × 1.5–3 mm. Petals 4–9 × 1.5–4 mm. Silique 8–20-seeded, constricted or not between the seeds, glabrous or hairy, 25–40 × 1.5–3 mm; beak conic or somewhat flattened, 0–1-seeded, < or = valves.

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

Flowering: Nov.–Feb.–(May); Fruiting: Nov.–Feb.–(May)