Galanthus have now been lost, and others not seen by the authors). They differ particularly in the size, shape, and markings of the flower, the period of flowering, and other characteristics, mainly of interest to the keen (even fanatical) snowdrop collectors, known as "galanthophiles", who hold meetings where the scarcer cultivars change hands. Double-flowered cultivars and forms, such as the extremely common "Galanthus nivalis" f. "pleniflorus" 'Flore Pleno', may be less attractive to some people, but they can have greater visual impact in a garden setting. Many hybrids have also occurred in cultivation. In the UK these species: and these cultivars:
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