The first two are blooming for the first time; they are either two stems of the same plant or two plants of the same seed batch sharing a pot, I can't tell right now! The seed was labelled as Helleborus orientalis/caucasicus. Not quite white, more cream to pale yellow. From the first photo I have to assume it has been in hidden bloom for quite awhile now, since the pollen is all gone. I admit I hadn't really been looking very hard.
Helleborus niger in full flower, the same plant as 17 March.