''Catathelasma evanescens'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 ...

in the family Biannulariaceae, and the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus ''

Catathelasma ''Catathelasma'' is a genus of fungi in the family (biology), family Biannulariaceae. Basidiocarps (fruit bodies) are agaric, agaricoid, with a conspicuous Universal veil, veil (leaving a double ring on the stem), Lamella (mycology), adnate to d ...

''. The species was described by Ruth Ellen Harrison Lovejoy in 1910.

Description and Distribution

The genus includes the commoner '' C. imperiale'' and ''C. ventricosum'', but the type species, ''C. evanescens'', seems extremely rare. In 1914 it was only known from the location of the initial find, which is at an altitude of 3500 m. in the

Medicine Bow Mountains The Medicine Bow Mountains are a mountain range in the Rocky Mountains that extend from northern Colorado into southern Wyoming. The northern extent of this range is the sub-range the Snowy Range. From the northern end of Colorado's Never Summer ...

of Wyoming. It is distinguished from the other species because the gills are fairly distant ("subdistant") and because it has a large persistent volva around the base of the stipe. The species name may refer to the

evanescent Evanescent may refer to: * Evanescent (dermatology), a class of skin lesions * "Evanescent" (song), a song by Vamps * Evanescent wave, a term applied to electromagnetic waves that decay exponentially See also * Evanescence (disambiguation) Ev ...

ring. The following summary is taken from Mrs. Lovejoy's original description. *Cap: 13 cm, broadly convex, white (but cream in the center). *Gills: White, very decurrent, "subdistant", with short and long ones mixed. *Stem: White, thick (4 cm.) but very short (1 cm.), with bulbous base, delicate evanescent ring, and large white persistent volva. *Spores: smooth, white, elliptical to fusiform, 14 - 17.5 × 3 - 5 μm.

References

External links

* {{Taxonbar, from=Q5051589 Fungi of North America Fungi described in 1910 Fungus species