Lycopodium obscurum – Tree Clubmoss

With their upright stems, horizontal branches, and finely divided foliage, these happy little plants resemble miniature evergreen trees, complete with small spore-bearing cones. Despite their tree-like appearances and a name that implies they are a type of Moss, these plants are actually closely related to Ferns. In an ideal location, Tree Club Moss will spread by underground stems to form a colony. Each year a new sterile shoot will form. The following year, that shoot will become fertile and will produce spore cones for three to four more years. Individual shoots live for a maximum of five years, at which point they will die back. In this time they will have established themselves sufficiently to either continue their spread or will have been growing for enough time to reproduce via spore. Most often seen in the forest understory, but sometimes grows in full or nearly full sun, especially in recently disturbed areas. Our experience has shown that these plants perform best in full sun when the soil biome is healthy and full of living roots. At the power lines which cut through the back portion of our farm, where we have established a diverse ground cover of low-growing, sand-loving native plants, Tree Club Moss thrives despite the canopy having been removed some decades ago. The spores of this plant have been used, along with those of the closely related Lycopodium clavatum, as a water repellent and as a source of flash powder. There are some medicinal uses for the spores as well, however the leaves are known to be toxic. These plants are legally protected from harvest in IN and NY.

A superb and rare choice for shade gardens, forest gardens, terrariums, foundation plantings (especially along the north end of structures), and to accent shady bare sites. Uniquely useful in shady bare spots under Oak trees, Rhododendrons, and Mountain Laurels. The plant is not browsed by herbivores.

Plant in dappled sun to full shade. Prefers a moist but well-drained, humusy soil. Naturally found growing in forest leaf litter. It is recommended to backfill the planting holes and surround new plantings with leaf mulch. Roots are subject to rot if they become too moist – this ancient plant mostly absorbs water through the foliage.

Recent taxonomic research has reclassified these plants. The genus Dendrolycopodium was proposed by the Pteridophyte Phylogeny Group (PPG) to elevate several subspecies of L. obscurum to the rank of species. Most of the proposed differences in species are contingent on geographic range or minute variations in plant morphology and spore shape. There are three Dendrolycopodium species present in the Northeastern US, but we cannot accurately confirm which ones are present on our farm with our current resources. To the best of our knowledge, under the PPG classification, this species is Dendrolycopodium obscurum.