Frost damage on Helleborus orientalis/caucasica, above. The first 2 photos are of the flowers featured a couple of days ago, the third is the plant recently shown with snow on it.
A group of potted Helleborus niger; those on the south side of the group (first photo) were seriously frost-damaged, others on the north side of the group (second photo), not.
Helleborus orientalis hybrid, the plant near the warmest foundation. Some flowers affected, some not. Predictably, those closest to the foundation are still fine.