Urban Commonality Rating

This rating reflects the likelihood of encountering any individual species on an urban tree. Several species can be found in most areas of the country and are extremely common on urban trees. Other species may be more common in some geographic areas are relatively rare in others, reflecting host distribution and/or climatic ranges. Some species […]


Thickness (Context and pore layer of individual mushroom caps or conks; Not groups) The thickness of individual fruiting structures can be used to separate out many of the wood decay fungi. The thickness is represents the measurement of individual fruiting structures such as an individual mushroom or single conk in a group of conks. The […]


The presence or absence of a stem (also called a stipe) can be an important identifying characteristic for some wood decay fungi. Most individual decay fungi on trees either form a stem or not, however several species can be found both with and without a stem. Absent Most wood decay fungi on living trees are […]

Shape and/or Texture

Shape and texture identify more closely the specific characteristics of Annual and Perennial fruiting structures. The categories reflect characteristics of mature conks, mushrooms or fruiting on a host. Developing fruiting structures should be allowed to fully mature before selecting one of the shape and texture categories. Annual include: Brittle or crumbly Tough or Leathery Fleshy/Mushroom; […]

Hymenium or Spore Producing Layer

The spore producing layer of wood decay fungi is called the hymenium. Each particular decay fungus species will produce one of the different types of spore bearing types: gills, pores, teeth, daedaloid or lamellae, or smooth. The observation of the type, appearance, size and location of the hymenium is critical to proper identification. Most decay […]

Hardwood or Conifer

Hardwood (syn. Angiosperm, broadleaf or deciduous) or Conifer (syn. Gymnosperm, evergreen, needled, coniferous) Host Most of the wood decay fungi are specific to either hardwood or coniferous hosts. This is a major selection point for identification of wood decay fungi. The number of decay fungi on conifer hosts is significant less than hardwood or deciduous […]

Fruiting Location

The general location a wood decay fungus fruits on a tree is an aid to identification. Four locations are identified here including on the ground attached to a root away from the base of the tree, on the butt or buttress roots of the tree, on the main trunk above the roots, and on the […]

Common Hosts

Most of the wood decay fungi are more common on genera or individual species of trees. Some have very wide host ranges. Common hosts are provided to narrow potential species of wood decay fungi. However, many wood decay fungi are reported from a broad range of hosts and appearance on a host different from “common […]

Annual or Perennial

Annual and perennial identify whether the fruiting of a decay fungus produces spores for a single growing season or part of a growing season (annual), or whether the fungus continues to produce a new pore layer and spores from the same fruiting structure over several or more years (perennial). The terms do not refer to […]