Galanthus (convolute). He merged "Nivalis" and "Plicati" into series "Galanthus", and divided "Latifolii" into two subseries, "Glaucaefolii" and "Viridifolii" . Early molecular phylogenetic studies confirmed the genus was monophyletic and suggested four clades, which were labelled as series, and showed that Davis' subseries were not monophyletic. An expanded study in 2013 demonstrated seven major clades corresponding to biogeographical distribution. This study used nuclear encoded nrITS (Nuclear ribosomal internal transcribed spacer), and plastid encoded "matK" (Maturase K), "trnL-F", "ndhF", and "psbK–psbI", and examined all species recognised at the time, and also two naturally occurring putative hybrids. The morphological characteristic of vernation that
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