Lycopodium dendroideum, tree groundpine, is a North American species of clubmoss. It is part of a complex of species colloquially known as groundpine, which taxa were formerly lumped into the species Lycopodium obscurum.  The species is native to Russia and also to the colder parts of North America (all states and provinces in Canada except Nunavut; northern and east-central United States including Alaska).
Lycopodium dendroideum prefers humus-rich, sandy, moist but not completely saturated soils. It is very similar to L. obscurum except for side shoots that are round in cross-section rather than flat, and having leaves all the same size.
This and other Lycopodium species have been commonly collected for decorative Christmas greenery. The spore of this species was also collected as Lycopodium powder for use in early photography, although this was not the preferred species for the purpose.
- "Lycopodium dendroideum". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 24 June 2015.
- Haines, Arthur. 2003. Families Huperziaceae and Lycopodiaceae of New England 84.
- Hickey, R. J. 1977. The Lycopodium obscurum complex in North America. American Fern Journal 67: 45--49.
- Biota of North America Program 2014 state-level distribution map
- Flora of North America, Lycopodium dendroideum Michaux, Fl. Bor.-Amer. 2: 282. 1803. Prickly tree club-moss, lycopode dendroïde