Photo by Gideon Chilton licensed under CC BY-NC 2.0
Few plants in temperate horticulture signal the end of winter better than snowdrops. Come February in the northern hemisphere, these herbaceous bulbs begin popping up, often through a layer of snow. They refuse to be beaten back by freak snow storms and deep frosts.
Snowdrops are native to a wide swath of the European continent. Like many spring ephemerals, they love moist, rich forests and will often escape into the surrounding environment. Taxonomically speaking, there are something like 20 species currently recognized. From what I can tell, this number has and continues to fluctuate each time someone takes a fresh crack at the group. What is certain is that the original distributions of many species have been clouded by a long history of associating with humans. For instance, whereas Galanthus nivalis is frequently thought of as being native to the UK, records show that it was only first introduced in 1770.
Map by Nalagtus licensed under CC BY-SA 4.0
Because we find them so endearing, snowdrops have become commonplace in temperate areas around the world. Reproduction for most of the garden escapees occurs mainly by division of their bulbs. As such, most plants you see in gardens and parks are clones. Pollination in snowdrops is frequently quite poor. This has been attributed to the lack of pollinating insects out and about during the cold months in which snowdrops flower. Bumblebees are some of the few insects up early enough to take advantage of their white blooms and, when seed set does occur, the plants rely on ants as their main seed dispersers.
Contrary to their ubiquitous presence around the globe, the IUCN lists some snowdrop species as near threatened in their home range. The genus Galanthus contains some of the most heavily collected and traded wild bulbs in the world. Pressure from the horticultural trade coupled with habitat destruction and climate change may push some species to the brink of extirpation throughout Europe in the not-so-distance future.
Further Reading: [1] [2] [3] [4]
http://www.arkive.org/snowdrop/galanthus-nivalis/