Prickly Tree-Clubmoss

Dendrolycopodium dendroideum

''Dendrolycopodium dendroideum'', synonym ''Lycopodium dendroideum'', known as 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 . The genus ''Dendrolycopodium'' is accepted in the Pteridophyte Phylogeny Group classification of 2016 , but not in other classifications, which submerge the genus in ''Lycopodium''.

''Dendrolycopodium dendroideum'' prefers humus-rich, sandy, moist but not completely saturated soils. It is very similar to ''D. obscurum'' except for side shoots that are round in cross-section rather than flat, and having leaves all the same size.