Diphasiastrum alpinum, the alpine clubmoss, is a species of clubmoss.<ref>Template:Cite web</ref> It was first described by Carl Linnaeus in his Flora Lapponica, 1737, from specimens obtained in Finland.
It has a circumpolar distribution across much of the northern parts of the Northern Hemisphere: much of Canada, the northwestern United States, northern and central Europe, Russia, China and Japan. It is an indicator of alpine tundra and boreal climates.<ref name=feis>Williams, Tara Y. 1990. Lycopodium alpinum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.</ref> It is found in mountains and moors often with Calluna and grasses.<ref name=r>Family Lycopodiaceae, genus Lycopodium; world species list</ref><ref>Template:Cite web</ref><ref>Biota of North America Program 2014 state-level distribution map</ref>
Diphasiastrum alpinum grows Template:Convert tall from stems which grow just under the surface of the ground. The leaves are hollow at the bases.<ref name=feis/> The female stems produce strobili up to Template:Convertlong.<ref name=wash>Lycopodium alpinum. Washington Burke Museum.</ref><ref>Flora of North America, Diphasiastrum alpinum (Linnaeus) Holub, 1975. Alpine club-moss, lycopode alpin </ref><ref>Flora of China, Lycopodium alpinum Linnaeus, 1753. 高山扁枝石松 gao shan bian zhi shi song </ref>