Hedge mustard
Sisymbrium officinale

Height: 30–60 cm (12–25 in.). Stem upper half strongly haired, usually short-haired, sometimes glabrous.

Flower: Corolla regular (actinomorphic), yellow–pale yellow, approx. 0.5 cm (0.2 in.) wide; petals four, 2–4 mm (0.08–0.16 in.) long. Sepals 4. Stamens usually 6, of which 4 long and 2 short. Gynoecium fused, a single carpel. Inflorescence a raceme, extending in fruiting stage.

Leaves: Alternate, stalked. Blade pinnately lobed, lobes usually short-haired (sometimes sparsely haired), terminal lobe large, triangular, with hastate base. Upper leaves commonly with only terminal lobe.