[1][2][3][4][5][6] Erysimum is characterised by star-shaped and/or two-sided) trichomes growing from the stem, with yellow, red, pink or orange flowers and multiseeded seed pods.

The genus name Erysimum is derived from the Ancient Greek erysimon (ἐρύσιμον, Sisymbrium officinale[7] or Sisymbrium polyceratium  [d],[8] the hedgenettle), itself from the word eryo (ἐρύω) meaning to drag[9] or eryso, a form of rhyomai (ῥύομαι),[citation needed] meaning "to ward off" or "to heal" in reference to its medicinal properties.

Growth is best in dry soils with very good drainage, and they are often grown successfully in loose wall mortar, hence the vernacular name.

There is a wide range of flower color in the warm spectrum, including white, yellow, orange, red, pink, maroon, purple and russet.

In addition, some species of weevils, like Ceutorhynchus chlorophanus, live inside the fruits feeding on the developing seeds.

Some mammalian herbivores, for example mule deer (Odocoileus hemionus) in North America, argali (Ovis ammon) in Mongolia, red deer (Cervus elaphus) in Central Europe, or Spanish ibex (Capra pyrenaica) in the Iberian Peninsula, feed on wallflower flowering and fruiting stalks.

[16][17] However, unlike almost all other genera in the Brassicaceae, Erysimum also accumulates cardiac glycosides, another class of phytochemicals with an ecological importance in insect defense.

The evolution of novel chemical defenses in plants, such as cardenolides in the genus Erysimum, is predicted to allow escape from herbivory by specialist herbivores and expansion into new ecological niches.

[29] The crucifer-feeding specialist Pieries rapae (white cabbage butterfly) is deterred from feeding and oviposition by cardenolides in Erysimum cheiranthoides.

)[1] This evolutionarily rapid expansion of the Erysimum genus has resulted in several hundred known species distributed throughout the northern hemisphere.

Erysimum cheiri is described as a medicinal herb in De Materia Medica by Pedanius Dioscorides (c. 70), which was the predominant European medical pharmacopeia for more than 1,500 years.