Sisymbrium altissimum L.

Annual herb. Stem erect, hairy at base, to 1 m tall. Rosette and lower stem lvs sparsely hispid especially below, pinnatifid, rarely almost 2-pinnatifid, 5–15–(30) × 1.5–7–(10) cm, with 5–9–(12) pairs of toothed triangular lobes. Upper stem lvs glabrous, smaller, pinnatifid with linear-filiform segments. Racemes often flexuous, ebracteate, suberect or spreading, glabrous, 10–30 cm long. Pedicels c. 5 mm long at flowering, elongating to up to c. 10 mm long at fruiting, glabrous. Sepals glabrous, 3–4 mm long, the outer pair with short horn at apex (most conspicuous in bud). Petals yellow, 6–8 mm long. Anthers at least 1 mm long; filaments = or slightly > sepals. Silique glabrous, spreading, linear-cylindric, (40)–70–110 × 1–1.5 mm; style 0.5–1 mm long. Seeds ovoid to oblong, brown, c. 0.8 mm long.

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

Flowering: Nov.–Mar.; Fruiting: Nov.–Mar.