The substrate is what the fruit-bodies are directly growing on (apart from those that occur among the remains of animal carcasses). For agarics that are growing on the ground and not obviously on larger pieces of wood, look carefully at what the fruit-body is attached to when picked to see if it is actually growing on litter or mulch (rather than the soil).

If fruit-bodies are growing on the trunks of tree ferns, do not choose any options for this feature because mycorrhizal agarics (which otherwise only grow on the ground) often grow on tree ferns trunks associated with living roots of other plants that grow in the trunks. If on tree ferns, look around to see if fruit-bodies are also growing elsewhere to decide on the correct choice for this feature.

Choose this state if: fruit-bodies are growing in dense patches of bryophytes, usually mosses. The fungi may be attached directly to the moss, and in some cases are parasitic on the moss, or the fungi may be growing on the ground.

In interpreting this character, look carefully around the moss patches to see if fruit-bodies are also growing in areas without moss (in which case choose soil or ground or wood as appropriate).

Take care in choosing this state when fungi are in moss patches that are growing on living trees or on large, old, fallen logs. If in doubt as to whether the fungi are on the wood, or among the moss, choose both states.