In mycology

Mycology

Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicinals , food and entheogens, as well as their dangers, such as poisoning or...

 a stipe refers to the stem or stalk-like feature supporting the cap

Pileus (mycology)

The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

 of a mushroom

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

. Like all tissues of the mushroom other than the hymenium

Hymenium

The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...

, the stipe is composed of sterile hyphal tissue. In many instances, however, the fertile hymenium extends down the stipe some distance. Fungi that have stipes are said to be stipitate.

The evolutionary benefit of a stipe is generally considered to be in mediating spore

Spore

In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

 dispersal. An elevated mushroom will more easily release its spores into wind currents or onto passing animals. Nevertheless, many mushrooms do not have stipes, including: cup fungi, puffball

Puffball

A puffball is a member of any of several groups of fungus in the division Basidiomycota. The puffballs were previously treated as a taxonomic group called the Gasteromycetes or Gasteromycetidae, but they are now known to be a polyphyletic assemblage. The distinguishing feature of all puffballs is...

s, earthstar

Geastraceae

The earthstars are the family Geastraceae of gasterocarpic basidiomycetes . It includes the genera Geastrum and Myriostoma. About sixty-four species are classified in this family, divided among eight genera....

s, some polypore

Polypore

Polypores are a group of tough, leathery poroid mushrooms similar to boletes, but typically lacking a distinct stalk. The technical distinction between the two types of mushrooms is that polypores do not have the spore-bearing tissue continuous along the entire underside of the mushroom. Many...

s, jelly fungi

Jelly fungi

The class Heterobasidiomycetes or jelly fungi is a paraphyletic group of several fungal orders: Tremellales, Auriculariales, Dacrymycetales. These fungi are so named because their foliose to irregularly branched fruiting body is, or appears to be, the consistency of jelly. Actually, many are...

, ergot

Ergot

Ergot or ergot fungi refers to a group of fungi of the genus Claviceps. The most prominent member of this group is Claviceps purpurea. This fungus grows on rye and related plants, and produces alkaloids that can cause ergotism in humans and other mammals who consume grains contaminated with its...

s, and smut

Smut (fungus)

The smuts are multicellular fungi, that are characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled and dust-like teliospores. They are mostly Ustilaginomycetes and can cause plant disease...

s.

It is often the case that features of the stipe are required to make a positive identification of a mushroom. Such distinguishing characters include:

1. the texture of the stipe (fibrous, brittle, chalky, leathery, firm, etc.)
2. whether it has remains of a partial veil
   Partial veil
   thumb|150px|right|Developmental stages of [[Agaricus campestris]] showing the role and evolution of a partial veilPartial veil is a mycological term used to describe a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics...
   
    (such as an annulus or cortina
   Cortina
   -Things:* Cortina * Ford Cortina, a medium-sized family car built by Ford of Britain from 1962 to 1982**Lotus Cortina, a 1963–1968 performance variant on the above...
   
   ) or universal veil
   Universal veil
   In mycology, a universal veil is a temporary membranous tissue that fully envelops immature fruiting bodies of certain gilled mushrooms. The developing Caesar's mushroom , for example, which may resemble a small white sphere at this point, is protected by this structure...
   
    (volva
   Volva (mycology)
   The volva is a mycological term to describe a cup-like structure at the base of a mushroom that is a remnant of the universal veil. This macrofeature is important in wild mushroom identification due to it being an easily observed, taxonomically significant feature which frequently signifies a...
   
   )
3. whether the stipes of many mushrooms fuse at their base
4. its general size and shape
5. whether the stipe extends underground in a root-like structure (a rhizome
   Rhizome
   In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
   
   )

When collecting mushrooms

Mushroom hunting

Mushroom hunting, mushrooming, mushroom picking, and similar terms describe the activity of gathering mushrooms in the wild, typically for eating...

for identification it is critical to maintain all these characters intact by digging the mushroom out of the soil, rather than cutting it off mid-stipe.