I grow cowslips from my own collected seed each year as its just so easy and they are great spring plants. I know that they can cross pollinate quite readily and often find variations in the flower colour, size and form.
This year, I came across this one. It has flowers bourne on upright stems although not as tall as cowslips. It looks great, the white edging to the petals real make the flower stand out. The downside is that the slugs love the flowers and regulary find the flowers gone within a day of flowering.