{{Short description|Species of fungus}} {{good article}} {{stack begin}} {{speciesbox | image = Roridomyces austrororidus 44180.jpg | image_caption = | taxon = Roridomyces austrororidus | authority = (Singer) Rexer (1994)<ref name="Rexer 1994"/> | synonyms_ref = <ref name="urlMycoBank: Roridomyces austrororidus"/><ref name="Horak 1978"/> | synonyms = *''Mycena austrororida'' <small>Singer (1962)</small> *''Mycena veronicae'' <small>Stevenson (1964)</small> }} {{mycomorphbox | name = ''Roridomyces austrororidus'' | hymeniumType = gills | capShape = convex | capShape2=conical | whichGills = adnate | stipeCharacter = bare | sporePrintColor = white | ecologicalType = saprotrophic | howEdible=inedible }} {{stack end}}

'''''Roridomyces austrororidus''''', commonly known as the '''austro dripping bonnet''', is a species of agaric fungus in the family Mycenaceae. Described as new to science in 1962 by American mycologist Rolf Singer, it is found in South America, New Zealand, and Australia, where it grows on rotting wood.

The fruit bodies (mushrooms) have several distinguishing characteristics that facilitate identification, including thick, white, mucilaginous stipes, and white to pale cream, convex caps that measure {{convert|1|–|2|cm|in|1|abbr=on}}. The gills are white, widely spaced, and have a fused or decurrent attachment to the stipe. Spores are smooth, ellipsoid, and measure about 9–15 by 6–9 micrometres. The smooth and white stipes are {{convert|4|–|6|cm|in|abbr=on}} long and {{convert|0.1|–|0.2|cm|in|2|abbr=on}} thick, and covered with a thick coating of gluten.

==Taxonomy, naming, and classification== The species was first described as ''Mycena austrororida'' by mycologist Rolf Singer in 1962, based on specimens he collected from Masatierra, in the Juan Fernandez Islands, Chile.<ref name="Singer 1962"/> Karl-Heinz Rexer transferred it to the newly circumscribed genus ''Roridomyces'' in his 1994 doctoral thesis.<ref name="Rexer 1994"/> The name ''Mycena veronicae'', published by New Zealand mycologist Greta Stevenson in 1964,<ref name="Stevenson 1964"/> is a synonym of ''M.&nbsp;austrororida''.<ref name="Horak 1978"/>

The mushroom is commonly known as the "austro dripping bonnet".<ref name="Young 2004"/> The specific epithet combines the Latin words ''austro'' (from ''australis'', "south")<ref name="Brookes 2004"/> and ''roridus'' ("wet with dew").<ref name="Quattrocchi 1999"/>

==Description== thumb|left|180px|The mucilaginous stipe is a characteristic feature The cap is shallowly convex to convex or irregularly convex, and with or without a shallow umbo, measuring up to {{convert|16|mm|in|abbr=on}} in diameter and up to {{convert|5|mm|in|1|abbr=on}} high. The cap margin is curved downward, sometimes slightly flared, and sometimes has translucent radial striations marking the positions of the gills underneath. The white flesh—thickest at the center of the cap—tapers gradually to the margin. The gills are broadly adnate (fused) to decurrent (running down the length of the stipe). The gill edges are either smooth and even, or may have minute teeth. The gills are well-spaced, with 16 to 24 gills extending fully from the cap margin to the stipe, and two or three tiers of interspersed lamellulae (short gills that do not extend fully from the cap margin to the stipe). The smooth, cylindrical stipe is up to {{convert|27|mm|in|abbr=on}} long, and up to {{convert|2.5|mm|in|1|abbr=on}} in diameter at the base, narrowing towards the top. It is hollow, silky to shiny, and mucilaginous—usually with thick slime at the base. Sometimes, there are short white hairs at the bottom of the stipe, although their presence is variable. The mushroom has no distinctive odor.<ref name="Grgurinovic 1995"/>

Spores are roughly ellipsoidal in shape with a Q ratio (the fraction of length/width) of 1.6, and dimensions of 9.4–15.4 by 6.2–9.0&nbsp;μm. They have a small, oblique apiculus, lack oil droplets, and are smooth with thin walls, and hyaline (translucent). The spores are acyanophilous and strongly amyloid, meaning they stain with Methyl blue and Melzer's reagent, respectively. The basidia (spore-bearing cells) are four-spored (rarely two-spored) and club-shaped with long, robust sterigmata up to 6.0&nbsp;μm long; they have clamp connections at their bases, and measure 35.3–49.6 by 10.3–14.4&nbsp;μm. ''Roridomyces austrororidus'' has two types of cheilocystidia (cystidia on gill edges). One is rare, broadly club-shaped, and tapers to a narrow stem; it measures 24.1–39.5 by 6.8–12.7&nbsp;μm. The other cheilocystidia are moderately dense to abundant, and form a sterile gill edge. They are cylindrical, measuring 27.5–70.4 by 5.4–10.4&nbsp;μm, and often have a swollen tip that splits into two, rarely three branches.<ref name="Grgurinovic 1995"/>

===Similar species=== The African species ''Roridomyces mauritianus'' is similar in appearance to ''R.&nbsp;austrororidus'', but can be distinguished by the brownish cap, and microscopically by its smaller spores (measuring 7–8 by 3.5–4.0&nbsp;μm), and its shorter (25–40&nbsp;μm), club-shaped basidia.<ref name="Robich 2001"/>

==Habitat and distribution== thumb|right|Fruit bodies grow on decaying wood. Like all members of its genus, ''Roridomyces austrororidus'' grows as a saprophyte on rotting wood. In Australia, the fungus fruits in clusters or groups on rainforest trees, decayed logs, fallen ''Eucalyptus'' branches, ''Bedfordia salicina'' logs and branches, and ''Nothofagus cunninghamii'' logs. Fruiting usually occurs after rainy periods from April to June, although the mushroom has also been collected in August.<ref name="Grgurinovic 1995"/> New Zealand collections have been reported to grow on ''Pinus'', ''Leptospermum'', and ''Ripogonum''.<ref name="Horak 1978"/> A study of fungal succession in a wet eucalypt forest in Tasmania demonstrated that ''R.&nbsp;austrororidus'' prefers mature forests (with at least 70 years of growth since the last wildfire), and fruits on small diameter wood—typically twigs with a width less than {{convert|15|mm|in|1|abbr=on}}.<ref name="Gates 2005"/>

''Roridomyces austrororidus'' occurs in Argentina,<ref name="Niveiro 2013"/> Chile, New Zealand,<ref name="Horak 1978"/> and Australia.<ref name="Grgurinovic 1995"/> Its Australian distribution includes Queensland, New South Wales, Victoria, Tasmania and Western Australia. Australian mycologist Tony Young suggests that the geographical distribution of the fungus indicates that its ancestor may have originated from the ancient continent Gondwana.<ref name="Young 2004"/> {{Clear}}

==References== {{Reflist|colwidth=30em|refs=

<ref name="Brookes 2004">{{cite book |author=Brookes I. |title=Chambers Concise Dictionary |url=https://books.google.com/books?id=iwWuY9tAVq8C&pg=PA77 |year=2004 |publisher=Allied Publishers |isbn=978-0-550-10072-6 |page=77}}</ref>

<ref name="Gates 2005">{{cite journal |vauthors=Gates GM, Ratkowsky DA, Grove SJ |title=A comparison of macrofungi in young silvicultural regeneration and mature forest at the Warra LTER Site in the southern forests of Tasmania |journal=Tasforests |year=2005 |volume=16 |pages=127–52 |url=http://cdn.forestrytasmania.com.au/assets/0000/0253/tasforests_16_10_web.pdf }}</ref>

<ref name="Grgurinovic 1995">{{cite journal |title=''Mycena'' in Australia: section ''Roridae'' |journal=Australian Systematic Botany |year=1995 |author=Grgurinovic C. |volume=8 |issue=4 |pages=537–47 |doi=10.1071/SB9950537}}</ref>

<ref name="Horak 1978">{{cite journal |title=''Mycena rorida'' (Fr.) Quél. and related species from the Southern Hemisphere |journal=Berichte der Schweizerischen Botanischen Gesellschaft |author=Horak E. |year=1978 |volume=88 |issue=1–2 |pages=20–29 |doi=10.5169/seals-62336}}</ref>

<ref name="Niveiro 2013">{{cite journal |vauthors=Niveiro N, Albertó E |title=Checklist of the Argentine Agaricales. 4. Tricholomataceae and Polyporaceae |journal=Mycotaxon |year=2013 |volume=121 |pages=1–97 (see p.&nbsp;81) |url=http://www.mycotaxon.com/resources/checklists/Niveiro-v121-checklist.pdf }}</ref>

<ref name="Quattrocchi 1999">{{cite book |author=Quattrocchi U. |title=CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms. Synonyms, and Etymology |url=https://books.google.com/books?id=2ndDtX-RjYkC&pg=PA2333 |year=1999 |publisher=CRC Press |isbn=978-0-8493-2678-3 |page=2333}}</ref>

<ref name="Rexer 1994">{{cite thesis |degree=Ph.D. |title=Die Gattung ''Mycena'' s.l., Studien zu Ihrer Anatomie, Morphologie und Systematik |author=Rexer K-H. |publisher=Eberhard-Karls-Universität Tübingen |location=Tübingen, Germany|year=1994 |language=de}}</ref>

<ref name="Robich 2001">{{cite journal |vauthors=Robich G, Hausknecht A |title=''Mycena mauritania'', a new species of sect. ''Roridae'' |journal=Österreichische Zeitschrift für Pilzkunde |year=2001 |volume=10 |pages=75–82 |url=http://www.landesmuseum.at/pdf_frei_remote/OestZPilz_10_0075-0082.pdf }}</ref>

<ref name="Singer 1962">{{cite journal |title=Basidiomycetes from Masatierra |author=Singer R. |journal=Arkiv før Botanik |volume=4 |series=2 |issue=5 |year=1962 |pages=370–400}}</ref>

<ref name="Stevenson 1964">{{cite journal |title=The Agaricales of New Zealand: V |journal=Kew Bulletin |author=Stevenson G. |year=1964 |volume=19 |issue=1 |pages=1–59 |jstor=4108283 |doi=10.2307/4108283}}</ref>

<ref name="urlMycoBank: Roridomyces austrororidus">{{cite web |url=http://www.mycobank.org/BioloMICS.aspx?Table=Mycobank&Rec=375302&Fields=All |title=''Roridomyces austrororidus'' (Singer) Rexer 1994 |publisher=International Mycological Association |work=MycoBank |access-date=2012-10-20}}</ref>

<ref name="Young 2004">{{cite book |title=A Field Guide to the Fungi of Australia |author=Young AM. |year=2004 |location=Sydney, Australia |publisher=University of New South Wales Press |page=157 |isbn=978-0-86840-742-5}}</ref>

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==External links== {{Commons}} *{{IndexFungorum|483234}}

{{Taxonbar|from=Q10656822}}

Category:Mycenaceae Category:Fungi of Australia Category:Fungi of New Zealand Category:Fungi of South America Category:Fungi described in 1962 Category:Taxa named by Rolf Singer Category:Fungus species