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.
Most wood decay fungi on living trees are attached directly to the trunk or root of a tree without a stem.
All of the fungi with a stem form annual conks or mushrooms. The stem may be lateral (attached on the side of the mushroom or conk) (Photograph 2) or central (attached in the middle of the mushroom or conk) (Photograph 3). Some of the root decay fungi that grow on buried roots may form a short stem if the root is just below the soil surface, or may develop a more extensive fungal pad when the root is deeper in the soil.