Dendrolycopodium is a small genus of clubmosses in the family Lycopodiaceae, order Lycopodiales, placed within the class Lycopodiopsida — the true clubmosses and their allies, among the oldest lineages of vascular plants. Under the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the genus sits in the subfamily Lycopodioideae.
All members share a distinctive growth form: erect to semi-erect, repeatedly branched stems that give the plants a tree-like or shrubby silhouette, which is reflected in the name. The genus includes a discrete group of species with similar morphologies, distinguishing them from the sprawling or trailing habit typical of many other lycophytes.
Taxonomic boundaries remain contested. Some authorities do not recognize Dendrolycopodium as a separate genus, folding it into the broader genus Lycopodium; when treated that way, the group is known as section Obscura. The Checklist of Ferns and Lycophytes of the World (as of June 2024) accepts five species, distributed across the cool-temperate and boreal forests of northern North America, northeastern Asia, and the Himalayas.
Distribution
Species occur in cool-temperate and boreal zones across northern and northeastern North America, northeastern Asia (including central Siberia), and the Himalayas and southwestern China. D. dendroideum and D. obscurum are the most widespread North American representatives; D. verticale is restricted to China and the Himalayas.
Taxonomy Notes
Dendrolycopodium is sometimes treated as section Obscura of the broader genus Lycopodium rather than as a distinct genus. The Pteridophyte Phylogeny Group (PPG I, 2016) places it in subfamily Lycopodioideae within Lycopodiaceae. GBIF lists the genus as accepted under Lycopodiales.
