Trond, your plant is E. x versicolor 'Sulphureum', an old standby that has proven its garden value for a nearly a century. I have this in a couple places, but my biggest patch is down at the lower wooded edge of my property, far out of reach of a hose, growing under dry dry dry Sugar Maples, and after 25 years neglected there, they still persist and grow and flower well.
Maggi, it's an important point you make. Many people here are sold on the idea these are "shade plants" for woodland gardens, when in fact, they revel in bright open light, a half day of sun is best for most compact and vigorous growth, best flowering potential, and more intense leaf coloring. They can be grown in full sun too, as long as they don't get totally parched.
I should show photos side-by-side of Epimedium "Mark's Star" (thanks for the name Wim
), where I grew several plants that got 1/2 day sun, and my original plants growing about 40' away in the north-facing constant shade of my house. The plants in shade all day, flowered 3 weeks later than those getting sun, those in sun were compact and amazingly floriferous, whereas those in full shadow grew more open and flowered well enough but modestly by comparison, a real eye-opener.
.....but that does not prevent my appreciation of these interesting plants. 
