Overview of Fungi Biology

While the structure of a mushroom can vary greatly from species to species, the edible Basidiomycota and Ascomycota types of fungi share in some basic morphology. But, just to confuse the matter, not all mushrooms have all these parts. These basic parts are the cap, gills, stem, ring, volva, spores and mycelium.

The cap of the mushroom is the topmost part and can be flat, conical or spherical and have a huge range of textures and colors. The color, texture and shape of a cap vary by species, age and conditions during the growth of the mushroom. The technical name for a cap is a pileus. The gills of the mushroom refer to the underside of the cap. The shape of the individual gills, their color, how and where they attach to the stem, and even their spacing all play a role in mushroom identification. Not all mushrooms have gills. Some, like porcinis, have pores. These are tiny, tightly packed tubes that resemble a sponge. Others, like lion’s mane, have teeth or needles instead of gills. Technically speaking, gills are called lamellae, and their function is the production and dispersal of spores.

Mushroom spores are microscopic, reproductive cells produced in the gills. Mycologists use the color, size and shape of the spores for species identification. By way of a spore print, you can also use spores to correctly and positively identify a foraged mushroom. You should never eat a mushroom that you can not completely and positively identify. As the saying goes, "When in doubt, throw it out." 

The ring of the mushroom is the remaining part of the partial veil and can be found on a mushroom stem. A partial veil is a thin piece of tissue that provides an extra layer of protection for the gills when the mushroom is young. As the mushroom matures, it ruptures the partial veil and exposes the gills. Sometimes, the remnants of the veil remain to form a ring around the stem. The ring may vary considerably among different species. People use the ring type, position and shape for the clarification and identification of mushrooms. 

The mushroom stem is referred to as the stipe and basically elevates the mushroom off of the substrate to aid in the dispersal of spores. Along with the other parts of the mushroom body, the size, shape and texture of the stem is used for mushroom identification. While some mushrooms have no stem at all, others have gills that extend all of the way down the steep, like you see in oyster mushrooms. Mycologists refer to mushrooms that have a stipe, or stem, as stipitate.

The volva or universal veil is a layer of tissue that protects immature mushrooms as  they grow out of the ground. Early in its growth the mushroom breaks through the universal veil, sometimes leaving a cup-like shape at the stem’s base. This is  the volva. The volva is very important when identifying Amanita mushrooms in the wild.

The majority of the fungus is actually beneath the earth. This portion of the fungus is known as the mycelium. The mycelium is composed of a vast network of strands, the hyphae, that can extend for thousands of acres  underneath the ground. The mycelium grows into or around the food source and secretes enzymes that digest the food externally. The mycelium then absorbs the digested nutrients and transports them through the mycelial network to where the fruiting bodies are being produced. The end result of this process is to enable the release of spores, thereby facilitating the reproduction and advancement of  the life and range of the species.