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 have been found on the surface of "C. nivalis" cysts. The unknown bacteria were not detected in control samples that did not contain "C. nivalis" which strongly suggests that it must be associated with the algae. Another bacterium, "Mesorhizobium loti", was found as contamination in a "C. nivalis" culture, but further testing suggested that this bacteria may be synthesizing vitamin B12 for the algae. In cryoconite holes "C. nivalis" can be found among bacteria, virus-like particles, ciliates, and Chlorophyte species. Ice worms have also been found to live preferentially under "C. nivalis" in glaciers, possibly using the algae as a