Only a handful of specialized non-conifer species of vegetation are able to survive the wet conditions of the Northern Forest. Flowering plants (Angiosperms) are rare in this lush forest. They have been replaced primarily by another highly versatile organism: lichen.
Lichens of previous times were small, low-growing, composite, symbiotic organisms. In the moisture-laden atmosphere of the Northern Forest, they have prospered, evolving into sturdy, treelike forms, growing up to 3 meters high. Gone are the soft fleshy bodies of their ancestors and in their place have developed robust trunks built up from dead fungal fibers laid down in the core. The understory of the Northern Forest is a tangle of such lichen trees. They achieve photosynthesis and absorb moisture by trailing feathery algal structures that hang like tattered curtains in the humid air. Spore sacs contain assemblages of both lichen and fungal spores, which explode on contact. The dispersal of these spores is aided by animals as they brush past the lichens, bursting the spore sacs as they go.
Slithersuckers have a symbiotic relationship with lichen trees in that nutrients from a slithersucker's meal will nourish the tree itself.