Galanthus and water if disturbed by floods. Some snowdrop species are threatened in their wild habitats, due to habitat destruction, illegal collecting and climate change. In most countries collecting bulbs from the wild is now illegal. Under CITES regulations, international trade in any quantity of "Galanthus", whether bulbs, live plants, or even dead ones, is illegal without a CITES permit. This applies to hybrids and named cultivars, as well as species. CITES lists all species but allows a limited trade in wild-collected bulbs of just three species ("G. nivalis", "G. elwesii", and "G. woronowii") from Turkey and Georgia (see Horticulture). A
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