Diphasiastrum complanatum,[4] common names groundcedar,[5] creeping jenny, or northern running-pine, is a species of clubmoss native to dry coniferous forests in colder northerly parts of the world.

Under the original name Lycopodium complanatum, this was an inclusive superspecies that included a number of other species now known to be biologically separate.

[6] Diphasiastrum complanatum is a perennial herb spreading by means of stolons that run along the surface of the ground.

The sporangium are in long-stalked densely cylindrical spore cones.

[6] As the species is currently recognized, it has been found in Canada, Greenland, northern and central Europe including montane regions of the British Isles, Russia, China, Japan, India, Thailand, and the northern United States.