Ta. Actually I have the book on Hellebores by Burrows and Tyler which is about as definitive as it can get for any genus of plants.
We grow Hh.x orientalis (hybridus),foetidus, x sternii,x ballardii, corsica (well sort of) and another one whose name eascapes me. Tried H. pupurescens but it did not survive and never had the money to buy any of the others!