moss growing on trees is an example of what
Moss Choice of substrate varies by species as well. Moss species can be classed as growing on: rocks, exposed mineral soil, disturbed soils, acid soil, calcareous soil, cliff seeps and waterfall spray areas, streamsides, shaded humusy soil, downed logs, burnt stumps, tree trunk bases, upper tree trunks, and tree branches or in bogs. Moss species growing on or under trees are often specific about the species of trees they grow on, such as preferring conifers to broadleaf trees, oaks to alders, or vice versa.[6] While mosses often grow on trees as epiphytes, they are never parasitic on the tree.
Lycopodium Lycopodium (from Greek lukos, wolf and podion, diminutive of pous, foot) is a genus of clubmosses, also known as ground pines or creeping cedar,[1] in the family Lycopodiaceae, a family of fern-allies (see Pteridophyta). They are flowerless, vascular, terrestrial or epiphytic plants, with widely branched, erect, prostrate or creeping stems, with small, simple, needle-like or scale-like leaves that cover the stem and branches thickly. The leaves contain a single, unbranched vascular strand and are microphylls by definition. The kidney-shaped or reniform spore-cases (sporangia) contain spores of one kind only (isosporous, homosporous) and are borne on the upper surface of the leaf blade of specialized leaves (sporophylls) arranged in a cone-like strobilus at the end of upright stems. The club-shaped appearance of these fertile stems gives the clubmosses their common name.