Erysimum mutabile
  Perennial wallflower
Location
The Terrace Border
Description: 
A shrubby perennial wallflower with narrow leaves, which hails   from the Canary Islands and Madeira. The original species had flowers which open pale yellow then age to mauve, blooming in spring.  
Site and Care:
Grow in  sun on well-drained   alkaline (chalky) soil, on the dry side. It   needs to be cut back after flowering to keep it compact, but it will   only last a few years. Propagate  from softwood cuttings.