The Corsican hellebore used to be known botanically as H. corsicus. It is a large perennial (ht 60 - 80cm) with bold, leathery, serrated-edged leaves of a deep green hue, providing a contrast to the clusters of many exquisite, pale-green, cup-shaped blooms which open in late autumn and last until early spring. It is a Mediterranean plant, and unlike some other hellebores, it will grow in sunny, well-drained soil on the dry side. However, it also seems to adapt to shadier sites, as long as the drainage is good, including dry positions near trees. It needs to be cut to the ground after flowering, as new stems will then grow to re-form the plant. Unlike the Orientalis Hybrid hellebores, it is not a long-lived plant, dying after a few years, but usually leaving behind it a creche of self-sown babies. These seedlings can be transplanted if handled carefully and moved when they are fairly small. It is not possible to divide the plant to propagate it.
This flower looks attractive with other plants from the Mediterranean, Madeira and the Canary Islands in bloom at the same time, such as Euphorbia characias subsp. wulfenii, Erysimum mutabile and Iris germanica. I also think it would be a great underplanting to shrubby Mahonia japonica, which flowers in winter and has similar foliage to this hellebore. These hellebores are useful as a cut flower.
It is best to buy these plants from a specialist nursery.