''Psathyrella aquatica'' is a species of

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

from

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, first described in the journal ''

Mycologia ''Mycologia'' is a peer-reviewed scientific journal that publishes papers on all aspects of the fungi, including lichens. It first appeared as a bimonthly journal in January 1909, published by the New York Botanical Garden under the editorship of W ...

'' in 2010. It represents the first ever report of a gilled

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

fruiting underwater.

Discovery

It was found by

Southern Oregon University Southern Oregon University (SOU) is a public university in Ashland, Oregon. It was founded in 1872 as the Ashland Academy, has been in its current location since 1926, and was known by nine other names before assuming its current name in 1997.Kre ...

professor Robert Coffan in the Rogue River in the U.S. state of

. Coffan and his colleagues, Darlene Southworth and Jonathan Frank, found the mushroom in 2005. The

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary i ...

department at Southern Oregon University confirmed that the mushroom was a unique discovery. Once their research was published, it was named one of the most significant species discovered in 2010. They have so far been discovered in a 1 kilometer stretch of the river, and have an observed fruiting season of mid-June to late September''Underwater_Mushroom – Mycological Society of America''. (n.d.). Retrieved February 25, 2022, from https://msafungi.org/underwater_mushroom/ Many scientists were skeptical about describing this mushroom as a new species because of the hundreds of similar looking species in the

Psathyrella ''Psathyrella'' is a large genus of about 400 species, and is similar to the genera '' Coprinellus'', ''Coprinopsis'', ''Coprinus'' and ''Panaeolus'', usually with a thin cap and white or yellowish white hollow stem. The caps do not self digest ...

family. Less than 1% of aquatic fungi are assumed to be discovered yet, and many are assumed to be microscopic, with only a small fraction thought to produce fruiting bodies.

Description

The fruiting body consists of a small convex cap and a long stipe. Its cap is brown, convex, and has gills underneath. The young mushroom develops a veil, which is lost as the mushroom grows to maturity. The mushroom's stipe appears to be quite strong, and is anchored up to 1.6 feet (0.5 m) deep in sediment, in order to stand up to the fast-moving river currents where it is primarily found. The stipe is covered in thin hair like structures. Spores released by the gills stay in gas bubbles underneath the gills before floating to the top of the water to spread. Underwater gills and ballistospores suggest that its underwater adaption is a relatively recent one. When synthetically grown, ''P. aquatica'' are known to only fruit (produce stipe and cap) underwater. A study done in 2014 by one of the original authors of the discovery paper showed that this species only produces sporocarps when completely submerged under cold water.

Habitat

The mushrooms are found growing out of water-logged wood, silt, and gravel, a fine volcanic substrate, and was observed growing from youth to maturity completely underwater over 11 weeks. The mushroom grows submerged under fast, cold, running water of the river. The water is spring fed, aerated, and contains lots of woody debris and is shallow in depth. They are found growing about a half a meter underneath the water. The mushroom is also found growing on land in either grassy banks, or on gravel or water-logged wood next to the river.

Ecosystem role

Though not enough is known about the species to consider it edible, scientist assume that it is a food source for small insects in the river. Though the river has low levels of

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

, nitrogen-fixing

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

near mushroom discovery sites suggests they might provide a source of nitrogen.

Taxonomy

The taxonomy of the species is in reference to the habitat of the mushroom is found in. Aquatica is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word meaning water or watery.''Latin Definition for: Aquaticus, aquatica, aquaticum (ID: 4328)—Latin Dictionary and Grammar Resources—Latdict''. (n.d.). Retrieved April 27, 2022, from http://www.latin-dictionary.net/definition/4328/aquaticus-aquatica-aquaticum

References

Aquatic fungi Psathyrellaceae Fungi of North America Fungi described in 2010 {{Psathyrellaceae-stub