''Catathelasma'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Biannulariaceae.

Basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

(fruit bodies) are

agaricoid An agaric () is a type of fungal fruiting body characterized by the presence of a pileus (cap) that is clearly differentiated from the stipe (stalk), with lamellae (gills) on the underside of the pileus. It is a type of mushroom (or toadstool), ...

, with a conspicuous

veil A veil is an article of clothing or hanging cloth that is intended to cover some part of the human head, head or face, or an object of some significance. Veiling has a long history in European, Asian, and African societies. The practice has be ...

(leaving a double ring on the stem), adnate to

decurrent ''Decurrent'' (sometimes decurring) is a term used in botany and mycology to describe plant or fungal parts that extend downward. In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petio ...

lamellae Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...

, and

amyloid Amyloids are aggregates of proteins characterised by a fibrillar morphology of typically 7–13 nm in diameter, a β-sheet secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. In the human ...

basidiospores A basidiospore is a reproductive spore produced by basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pr ...

. The genus is separated on DNA characteristics as well as morphology. Species are known from North America, Europe, and Asia and are

ectomycorrhizal An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobion ...

, forming an association with the living roots of trees.

Taxonomy

The genus ''Catathelasma'' was originally described in 1910 by American botanist and

mycologist Mycology is the branch of biology concerned with the study of fungi, including their taxonomy, genetics, biochemical properties, and use by humans. Fungi can be a source of tinder, food, traditional medicine, as well as entheogens, poison, and ...

Ruth Ellen Harrison Lovejoy with '' C. evanescens'' as the type species. in 1922 the Austrian botanist

Günther Beck von Mannagetta und Lerchenau Günther Ritter Beck von Mannagetta und Lerchenau (25 August 1856 in Pressburg, modern Bratislava – 23 June 1931 in Prague) was an Austrian botanist. Life Ritter Beck-Mannagetta, son of a state prosecutor, studied at the University of Vienna, ...

referred the European species ''Armillaria imperialis'' to his new genus ''Biannularia''. For a time ''Catathelasma'' and ''Biannularia'' were regarded as separate (though closely related) genera, as for instance in a 1936 paper by

Rolf Singer Rolf Singer (June 23, 1906 – January 18, 1994) was a German mycologist and Taxonomy (biology), taxonomist of gilled mushrooms (agarics). He wrote the book "The Agaricales in Modern Taxonomy (biology), Taxonomy". He fled to various countries d ...

. Later Singer united the genera using Lovejoy's earlier name. Recent DNA research confirms this synonymy.

Etymology

Lovejoy's original description states that: According to Genaust's etymological dictionary of botanical names, "Catathelasma" comes from Ancient Greek words "kata" ( - downwards) and "thelasma" ( - meaning "the act of suckling"). He says that the reason for this construction is unclear, but suggests that the author is comparing the shape made by the gills running down the stem with a teat stretched out during suckling. "

Decurrent ''Decurrent'' (sometimes decurring) is a term used in botany and mycology to describe plant or fungal parts that extend downward. In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petio ...

" means "running down the stem" and another possible connection with Lovejoy's description is that "katatheo" () means "I run down". However it is difficult to see how that could logically give rise to the noun "Catathelasma".

Description

''Catathelasma'' species are stocky, ''

Tricholoma ''Tricholoma'' is a genus of fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms ...

''-like fungi, with adnate to

lamellae (gills), a double veil (giving the stipe two rings), a stipe that is tapered to the base and rooting (often buried), and a mealy smell. At the microscopic level they have oblong to cylindrical,

spores, a bilateral gill trama, and

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

with

clamp connections A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of basidiomycete fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), recei ...

Habitat and distribution

Species are

, growing on the ground under conifers. They are known from continental Europe, North and Central America, and Asia.

Edibility

Some species of ''Catathelasma'' are edible and are collected for food in China, Guatemala, and Russia.

References

{{Taxonbar, from=Q2707526 Agaricales genera