Lycopodium lagopus is an evergreen perennial clubmoss with creeping horizontal stems and stalked strobilii (cone-like reproductive structures). This species occurs occasionally in Denali (although it may be overlooked) in subalpine woodlands, shrublands and heaths. The erect stems grow 10-25 cm tall, arising at more or less regular intervals. The leaves are scale-like, narrow, appressed and over-lapping on the stem. Leaves are tipped with a white hair. Erect branches are topped with a single spore-producing stalked strobilus. The stalked strobilii distinguish it from Lycopodium annotinum. Diphasiastrum complanatum is another clubmoss with stalked strobilii, but that species is much more richly branched and the strobilii are often produced several to a stem.
Lycopodium lagopus is an evergreen plant and can begin photosynthesis soon after the snow melts. Spores are usually produced mid-summer.
The visible portion of Lycopodium lagotis is a diploid sporophyte. Like all clubmosses, these plants are produced from a haploid lifecycle, which lives underground and is entirely dependent on mycorrhizae for its survival. The haploid gametophyte self-fertilizes and produces an independent, photosynthetic sporophyte (the plant described and pictured). sporophytes produce single-celled spores, which are wind-dispersed and develop into new underground gametophytes.
The clubmosses (Diphasiastrum and Lycopodium are used by the Dena'ina to make an eye wash (Kari 1995). Other species in these genera which occur primarily in forested areas were used medicinally by indigenous people throughout North America and Europe (Moerman 1998, Schofield 1989).
L. lagopus is an incompletely circumpolar species, ranging from Greenland, Eurasia, and across northern North America. In North America, this species occurs from Alaska eastward to Labrador and south to the Great lakes region. In Alaska, it grows statewide except is rare or absent from the Aleutian chain, southeast panhandle, and Arctic slope. In Denali, this species occurs in isolated localities on both sides of the Alaska Range.
Lycopodium lagopus is found in the park at elevations from 601 m to 1029 m with an average site elevation of 842 m. Slope angle of sites where L. lagopus is found ranged from 2 to 35 degrees with an average angle of 18 degrees.