(species Helleborus niger), small poisonous perennial herb of the buttercup family (Ranunculaceae), known for its tendency to bloom from late autumn to early spring, often in the snow. It has evergreen compound leaves, of seven or more leaflets arranged like the fingers on a hand, that arise directly on leafstalks from the crown of the plant. The striking flowers, of five coloured sepals, are 5 to 7.5 cm (2 to 3 inches) across, are whitish to pinkish green, and appear during the winter, often at Christmas, in mild climates and in late spring in colder areas. Improved varieties include "Altifolius," somewhat taller, and "Potter's Wheel," with broader sepals. The Christmas rose flourishes in moist soil and partial shade in mild climates or in protected locations in colder areas and is sometimes forced to bloom in the greenhouse.
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