''Calliergon giganteum'', the giant spearmoss, giant calliergon moss, or arctic moss, is an

aquatic plant Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...

found on lake beds in

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...

regions. It has no wood stems or flowers, and has small rootlets instead of roots. ''Calliergon giganteum'' survives in the cold climate by storing

nutrient A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

s to be used in the formation of new leaves in the spring. It is one of about 2000 plant species on the tundra, most of which are mosses and lichens. The plant is eaten by migrating animals such as birds. The ground cover of ''Calliergon giganteum'' in the arctic has a warming effect which other plants benefit from. "Calliergon giganteum" grows to be about 8 cm tall.

References

Flora of Bulgaria Hypnales {{bryophyte-stub