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Lycopodium dendroideum Michx.

Groundpine

Lycopodiaceae (Clubmoss)

Synonym: Lycopodium obscurum L. var. dendroideum (Michaux) D.C. Eaton

General Description: An evergreen perennial that resembles a miniature tree. The scattered, branching stems are 12-30 cm tall arising from subterranean rhizomes. Stems and branches are densely covered by 6 (8) ranks of narrow, sharp-pointed, spreading leaves, 2-6 mm long. The sessile, non-green, cone-like strobili located at the tips of erect branches vary from 1 to 6 cm tall. The densely arranged sporophylls are broadly lance-shaped and about 3.5 mm long.

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Illustration.

Field Identification Tips: The miniature tree-like habit is distinctive. This is also the only clubmoss in northern Idaho with rhizomes deep underground.

Phenology: Produces spores in July.

Similar Species: There are several other clubmoss species in northern Idaho. Lycopodium annotinum has mostly unbranched stems and leafy horizontal stems along the surface, not deep underground. Lycopodium clavatum has pedunculate strobili and horizontal stems along the surface. Diphasiastrum complanatum (Syn. = L. complanatum) has flattened branches and scale-like leaves, D. sitchense (Syn. = L. sitchense) has horizontal stems at the surface or only shallowly buried, and leaves in 4-5 ranks. Conifer seedlings have a taproot rather than rhizomes.

Habitat: Moist coniferous forests in valley and lower montane areas. In Idaho, particularly in cold air drainage and frost pocket areas.

Global Distribution: Boreal North America and Asia; southward in the United States to the northeastern and Great Lake states, Washington, northern Idaho, northwestern Montana, and scattered stations further south.

Idaho Distribution: Western Bonner County in the Idaho Panhandle.

References:

Flora North America Editorial Committee. 1993. Flora of North America, Vol. 2. Pteridophytes and Gymnosperms. Oxford University Press, Inc., New York. 475 pp.

Montana Natural Heritage Program. Montana rare plant field guide. Available at: http://nhp.nris.state.mt.us.