Smelly wallflower

Erysimum odoratum is a biennial to short-lived perennial herb of the mustard family Brassicaceae, formerly often treated as a synonym of Erysimum hieraciifolium. The plant forms an erect, sparsely branched stem typically 30 to 80 cm tall, clothed in narrow, lanceolate to oblong leaves with shallowly toothed margins and a covering of fine appressed hairs. In late spring and summer it bears terminal racemes of fragrant, four-petalled cruciferous flowers in a clear yellow, the petals long-clawed and arranged in the characteristic cross shape of the family. The flowers give way to slender, elongate siliques borne on short stout pedicels, opening at maturity to release small seeds. Its native range extends from Central Europe eastwards to Ukraine, where it grows on dry calcareous slopes, rocky banks, forest margins and open grasslands.