Marasmiellus

Marasmiellus is a genus of fungi in the family Omphalotaceae (synonym to Marasmiaceae). The widespread genus, circumscribed by American mycologist William Murrill in 1915,[1] contains over 250 species.[2] The name comes from the Greek marasmus meaning wasting.

Marasmiellus
Aestchen-Zwergschwind (2).jpg
Marasmiellus ramealis
Scientific classification e
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Marasmiaceae
Genus: Marasmiellus
Murrill (1915)
Type species
Marasmiellus juniperinus
Murrill (1915)
Species

See text.

Morphology and life cycleEdit

The morphology of Marasmiellus has received little attention compared to other genera of Omphalotaceae, mainly due to their uncolorful pileus, small basidiocarps, and little variation in morphological characters. These factors complicate delimitations of species within this genus. Species of Marasmiellus have prostrate and diverticulate hyphae, which have no clear orientation. However, it has been observed that outher hyphae can aggregate in fascicles and be radially oriented. Furthermore, cheilocystidia arise from horizontal hyphae and are frequently embedded in the hymenium, often being prostrate. Some species of Marasmiellus use basidiospore germination, and distuiguishing different genera based on reproduction would depend on the speed of germination. During germination spores 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 agarics, by allowing rapid colonizations.[3][4] Their basidiocarps are collybioid or omphalioid and they have a white spore print. The cutis consis of a pileipellis, which sometimes transitions into a trichoderm, either with or without Rameales-structure.[5]

EcologyEdit

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, degrading leafy and woody remains. Some species are parasitic and attack certain plants that are economically important, such as sugar cane, maize, bananas, and coconut palms.[6] Observations of rhizomorph-forming species of Marasmiellus have also been confirmed (e.g Marasmiellus tenerrimus var setulosu and Marasmiellus opacu).[7]

TaxonomyEdit

 
Marasmiellus candidus (Bolton) Singer

Marasmiellus only represented three species when it was first described by William Murrill (Marasmiellus inconspicuous Murrill (Cuba), Marasmiellus purpureus (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.[4] Marasmiellus was traditionally included in Tricholomataceae R. Heim ex Pouzar,[8] but later DNA studies showed that parts of the genus belong to Omphalotaceae, which was described by A. Bresinsky in 1985 and is considered a synomyn to Marasmiaceae. Furthermore, several studies show that the Marasmiellus branched as multiple polyphyletic and artificial groups.[9][4] This has led to conflict surrounding its position relative to Gymnopus, 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.[10][9]

SpeciesEdit

See alsoEdit

ReferencesEdit

  1. ^ Murrill WA. (1915). "North American Flora". 4 (9): 237–69. {{cite journal}}: Cite journal requires |journal= (help)
  2. ^ Kirk PM, Cannon PF, Minter DW, Stalpers JA (2008). Dictionary of the Fungi (10th ed.). Wallingford, UK: CAB International. p. 401. ISBN 978-0-85199-826-8.
  3. ^ Petersen, Ronald H.; Gordon, Scott A. (November 1994). "Mating Systems in Hymenomycetes: New Reports and New Species". Mycologia. 86 (6): 743. doi:10.2307/3760587. ISSN 0027-5514. JSTOR 3760587.
  4. ^ a b c Mata, Juan L.; Hughes, Karen W.; Petersen, Ronald H. (June 2004). "Phylogenetic placement of Marasmiellus juniperinus". Mycoscience. 45 (3): 214–221. doi:10.1007/S10267-004-0170-3. S2CID 84299937.
  5. ^ Chun-Ying, Deng; Tai-Hui, Li; Bin, Song (2011-08-10). "A revised checklist of Marasmiellus for China Mainland". Czech Mycology. 63 (2): 203–214. doi:10.33585/cmy.63209. ISSN 1211-0981.
  6. ^ Herbarium Bogoriense, Botany Division, Research Center for Biology, Indonesian Institute of Sciences; Retnowati, A. (2018-05-24). "The species of Marasmiellus (Agaricales: Omphalotaceae) from Java and Bali" (PDF). Gardens' Bulletin Singapore. 70 (1): 191–258. doi:10.26492/gbs70(1).2018-17.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ^ Desjardin, Dennis E.; Gordon, Scott A.; Petersen, Ronald H. (January 1993). "Observations on two rhizomorph-forming species of Marasmiellus". Mycological Research. 97 (1): 111–122. doi:10.1016/S0953-7562(09)81147-7.
  8. ^ Dennis, R. W. G.; Singer, R. (March 1974). "The Genera Marasmiellus, Crepidotus and Simocybe in the Neotropics". Mycologia. 66 (2): 382. doi:10.2307/3758379. JSTOR 3758379.
  9. ^ a b Wilson, Andrew W.; Desjardin, Dennis E. (May 2005). "Phylogenetic relationships in the gymnopoid and marasmioid fungi (Basidiomycetes, euagarics clade)". Mycologia. 97 (3): 667–679. doi:10.1080/15572536.2006.11832797. ISSN 0027-5514. PMID 16392255. S2CID 218589623.
  10. ^ Oliveira, Jadson J. S.; Vargas-Isla, Ruby; Cabral, Tiara S.; Rodrigues, Doriane P.; Ishikawa, Noemia K. (May 2019). "Progress on the phylogeny of the Omphalotaceae: Gymnopus s. str., Marasmiellus s. str., Paragymnopus gen. nov. and Pusillomyces gen. nov". Mycological Progress. 18 (5): 713–739. doi:10.1007/s11557-019-01483-5. ISSN 1617-416X. S2CID 115153522.