Stem

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 attached directly to the trunk or root of a tree without a stem.

Photograph 1. Fruiting of a perennial conk attached directly to the trunk of a tree without a stem.
Photograph 1. Fruiting of a perennial conk attached directly to the trunk of a tree without a stem.

Present

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.

Photograph 2. Lateral (attached on the side of the mushroom) stem of an annual wood decay fungus.
Photograph 2. Lateral (attached on the side of the mushroom) stem of an annual wood decay fungus.
Photograph 3. Central (attached in the middle of the mushroom) stems on a group of mushrooms of Armillaria tabescens.
Photograph 3. Central (attached in the middle of the mushroom) stems on a group of mushrooms of Armillaria tabescens.