''Marasmiellus'' 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 ...

Omphalotaceae The Omphalotaceae are a family (biology), family of fungi in the order (biology), order Agaricales. Basidiocarps (fruit bodies) are most frequently agarics (gilled mushrooms), but occasionally corticioid (in the genus ''Brunneocorticium'') or por ...

. The widespread genus,

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by American mycologist

William Murrill William Alphonso Murrill (October 13, 1869 – December 25, 1957) was an American mycologist, known for his contributions to the knowledge of the Agaricales and Polyporaceae. In 1904, he became the assistant Curator at the New York Botanical G ...

in 1915, contains over 250 species. The name comes from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

marasmus Marasmus is a form of severe malnutrition characterized by energy deficiency. It can occur in anyone with severe malnutrition but usually occurs in children. Body weight is reduced to less than 62% of the normal (expected) body weight for the ...

'' meaning ''wasting''.

Morphology and life cycle

The morphology of ''Marasmiellus'' has received little attention compared to other genera of ''

'', mainly due to their uncolorful pileus, small

basidiocarp 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 ...

s, and little variation in morphological characters. These factors complicate delimitations of species within this genus. Species of ''Marasmiellus'' have prostrate and diverticulate

hypha 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 ...

e, which have no clear orientation. However, it has been observed that other hyphae can aggregate in fascicles and be radially oriented. Furthermore,

cheilocystidia A cystidium (: cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that are oft ...

arise from horizontal hyphae and are frequently embedded in the

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 oth ...

, often being prostrate. Some species of ''Marasmiellus'' use

basidiospore 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 Ploidy () is the number of complete sets of chromos ...

germination, and distinguishing different genera based on reproduction would depend on the speed of germination. During germination

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s of Marasmiellus tend to disperse in dilution platings. Some species are tetrapolar. Additionally, no bipolar or amphithallic taxa in this genus have been reported, which is unexpected, as this mating behavior is common for tropical

agaric 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) ...

s, by allowing rapid colonizations. Their basidiocarps are collybioid or omphalioid and they have a white spore print. The cutis consis of a

pileipellis The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes ...

, which sometimes transitions into a trichoderm, either with or without Rameales-structure.

Ecology

Species of ''Marasmiellus'' are distributed around tropical and sub-tropical forested areas around the world, where they play a significant ecological role by being

saprotrophic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

, degrading leafy and woody remains. Some species are

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

and attack certain plants that are economically important, such as sugar cane, maize, bananas, and coconut palms. Observations of

rhizomorph Mycelial cords are linear aggregations of parallel-oriented hyphae. The mature cords are composed of wide, empty vessel hyphae surrounded by narrower sheathing hyphae. Cords may look similar to plant roots, and also frequently have similar functi ...

-forming species of ''Marasmiellus'' have also been confirmed (e.g ''Marasmiellus tenerrimus'' var ''setulosu'' and ''

Marasmiellus opacu ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

'').

Taxonomy

''Marasmiellus'' only represented three species when it was first described by

(''

Marasmiellus inconspicuous ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

'' Murrill (Cuba), ''

Marasmiellus purpureus ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

'' (Berk. & Curt.) Murrill (Cuba), and '' Marasmiellus juniperinus'' Murrill (Jamaica)). Currently the genera consists of more than 250 species, of which the type species, ''M. juniperinus,'' remains the same as when the genera was first described. ''Marasmiellus'' was traditionally included in ''

Tricholomataceae The Tricholomataceae are a large family of fungi within the order Agaricales. Originally a classic "wastebasket taxon", the family included any white-, yellow-, or pink-spored genera in the Agaricales not already classified as belonging to e.g. t ...

'' R. Heim ex Pouzar, but later DNA studies showed that parts of the genus belong to

'','' which was described by A. Bresinsky in 1985. Furthermore, several studies show that the ''Marasmiellus'' branched as multiple

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

and artificial groups''.'' This has led to conflict surrounding its position relative to ''

Gymnopus ''Gymnopus'' is a genus of fungus in the family Omphalotaceae. The genus has a widespread, cosmopolitan distribution and contains about 300 species. History and classification The type species for ''Gymnopus'', '' Gymnopus fusipes,'' dates ba ...

'', and has resulted in two opposing views regarding their taxonomy: 1) ''Marasmiellus'' is encompassed within ''Gymnopus'' (inclusive), or 2) ''Marasmiellus'' remains a distinct genus from ''Gymnopus'' (restrictive). The most recent studies have shown that the second hypothesis is the strongest, placing ''Marasmiellus'' as a separate genus, but more research is required to confirm this.

Species

Marasmiellus cubensis ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

Marasmiellus gomez-pompae ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

Marasmiellus inodermatoides ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

'' *'' Marasmiellus juniperinus'' *'' Marasmiellus junquitoensis'' *'' Marasmiellus keralensis'' *''

Marasmiellus kindyerracola ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

Marasmiellus musacearum ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

'' *'' Marasmiellus nanus'' *'' Marasmiellus napoensis'' *'' Marasmiellus nivosus'' *'' Marasmiellus nodosus'' *''

Marasmiellus nothofagineus ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

Marasmiellus polyphyllus ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

'' *'' Marasmiellus potamogeton'' *'' Marasmiellus potassiovirens'' *'' Marasmiellus praeacutus'' *'' Marasmiellus primulae'' *'' Marasmiellus primulinus'' *'' Marasmiellus pruinosulus'' *'' Marasmiellus pseudogracilis'' *'' Marasmiellus pseudoparaphysatus'' *'' Marasmiellus pseudoramealis'' *'' Marasmiellus pulchellus'' *'' Marasmiellus pusillimus'' *'' Marasmiellus pygmaeus'' *'' Marasmiellus quercinus'' *'' Marasmiellus radiatim-plicatus'' *''

Marasmiellus ramealis ''Marasmiellus ramealis'' is a species of mushroom-forming fungus of the family Marasmiaceae. External links

* Fungi described in 1788 Marasmiaceae Fungus species {{Marasmiaceae-stub ...

Marasmiellus tener ''Marasmiellus'' is a genus of fungi in the family (biology), family Omphalotaceae. The widespread genus, circumscription (taxonomy), circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the ...

'' *''

Marasmiellus tenerrimus ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Mor ...

'' *'' Marasmiellus tetrachrous'' *'' Marasmiellus thaxteri'' *'' Marasmiellus trabutii'' *'' Marasmiellus trichodermialis'' *'' Marasmiellus tricolor'' *'' Marasmiellus tropicalis'' *'' Marasmiellus troyanus'' *'' Marasmiellus ugandensis'' *'' Marasmiellus umbilicatus'' *'' Marasmiellus umbonifer'' *'' Marasmiellus usambarensis'' *''

Marasmiellus vaillantii ''Marasmiellus'' is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek ''marasmus'' meaning ''wasting''. Morp ...

'' *'' Marasmiellus varzeae'' *'' Marasmiellus vernalis'' *'' Marasmiellus vinosus'' *'' Marasmiellus violaceogriseus'' *'' Marasmiellus violae'' *'' Marasmiellus virgatocutis'' *'' Marasmiellus viridifuscus'' *'' Marasmiellus volvatus'' *'' Marasmiellus xerophyticus'' *'' Marasmiellus yalae''

References

{{Taxonbar, from=Q890404 Marasmiaceae Agaricales genera Taxa named by William Alphonso Murrill

Morphology and life cycle

Ecology

Taxonomy

Species

See also

References