Erysimum x cheiri

Native to southeastern Europe, particularly Greece, this perennial hybrid subshrub is often grown as a biennial or annual in gardens. Narrow, pointed leaves support clusters of fragrant, four-petaled flowers in spring. Yellow, orange, brown, and purple forms are cultivated, and the stems are used as cut flowers. It can establish in old walls and stone crevices. Slender seed pods split open when ripe. It has been introduced to Ecuador, New Zealand, and much of Europe. Photographed in Quito, Ecuador, and Virginia.