This is a new cultivar of unknown source (may be it is Dutch) which looks close to C. calceolus but its flowers are much smaller. Not even half the size. In general it is said that hybrids are a bit easier to grow and that is the case here as well: I planted it last year (from a pot-grown speciman with two flowers) and it surprised me now with three flowers and we had a nasty winter with many losses. Heranne