Galanthus leaves (vernation). In the era of molecular phylogenetics this characteristic has been shown to be unreliable and now seven moleculary defined clades are recognised corresponding to the biogeographical distribution of species. New species continue to be discovered. Most species flower in winter, before the vernal equinox (20 or 21 March in the Northern Hemisphere), but some flower in early spring and late autumn. Snowdrops are sometimes confused with the two related genera within the tribe Galantheae, snowflakes "Leucojum" and "Acis". All species of "Galanthus" are perennial petaloid herbaceous bulbous (growing from bulbs) monocot plants. The genus is characterised by the
Chlamydomonas nivalis such that it is covered by the carotenoid globules full of astaxanthin that will provide protection against UV radiation. The majority (91%) of astaxanthin derivatives are stored in its monoester form within dormant "C. nivalis" red cysts. Astaxanthin is the pigment that makes the cell appear deep red. Other pigments that can also be found in "C. nivalis" include violaxanthin and fadonirubin. Visible algal blooms could be a crucial determinant of surface albedo. It has been suggested that algal blooms partially composed of "C. nivalis" may contribute to lowering ice and snow albedo. The red coloured pigments produced by the