Also know as Erysimum, this is the original European wallflower which is common in the wild right across the continent from Greece to the UK. Its value for bees is that it flowers, bright yellow, from March through to May providing mainly nectar. It can even have a second batch of flowers later if it is lightly pruned after the first flowering. It is sometimes categorised as a biennial but I find that if left to its own devices its more of a short lived perennial. After the second year the plants tend to get a bit woody and 'leggy' but produce masses of seedlings so you just need to
1, dont cut off the seed heads until they have split open and dropped
2, ensure that you dont weed them out by mistake and you will have plenty of new plants every year (and probably spare to give to your friends).
Both of these activities can be served perfectly by completely ignoring them!! This will be great news if your are planting for bees in a wildlife area and for those who like to keep a tidy garden then just be a bit careful.