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 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