Thlaspi arvense L.

Annual glabrous herb. Stems erect, simple or branched above, foetid when crushed, 20–60 cm tall. Lvs entire to dentate. Lower lvs ovate to elliptic to spathulate, narrowed to base, withering at flowering, c. 2–4 × 1–2 cm. Upper lvs amplexicaul, ovate to oblanceolate, c. 2–4 × 0.5–1 cm. Racemes 10–30 cm long; pedicels erecto-patent at flowering, spreading at fruiting. Sepals spreading, 1.5–2 × c. 1 mm. Petals white, 2.5–4 × 0.8–1 mm. Silicle obovate to ± circular, deeply notched at apex, 1–1.5 × 0.8–1.5 cm; valves reticulately veined; wing to 5 mm wide; stigma ± sessile in notch of silicle. Seeds ovoid, furrowed, dark brown, not winged, c. 2 mm long.

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

Flowering: (Jul.)–Oct.–Jan.–(May); Fruiting: (Jul.)–Oct.–Jan.–(May)