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 optimal position in the snow for moisture content, light, and temperature. When in the immotile cyst stage, the "C. nivalis" cells must depend on the flow of meltwater to move it by chance to a favourable area. The temperatures in which this species can survive in ranges from below 0 °C to just above 20 °C. Growth is slow when temperatures are below 5 °C. At 5-15 °C the growth of "C. nivalis" cells can outperform the growth of C. reinhardtii cells. Both species grow at the same rate at 20-25 °C. The growth of "C. nivalis" is suppressed when