Once known as Cheiranthus mutabilis, this is a shrubby perennial wallflower with narrow leaves, which hails from the Canary Islands and Madeira. The original species (ht 80 cm, pictured above) had flowers which open pale yellow then age to mauve, blooming in late winter and spring. There is a cultivar of this Erysimum called 'Variegatum' that has cream-striped leaves. The cultivar 'Winter Joy' (ht 80 cm, pictured below) has pretty mauve flowers, which bloom from winter into spring. They have a light scent. The plants enjoy a sunny, well-drained position, on the dry side, with a little lime added to the soil. They need to be cut back after flowering to keep them compact, but they will only last a few years: propagate from cuttings.
Erysimum species are regarded as a good source of food for bees and hoverflies.