Rhodotus

The type species of genus Rhodotus was originally described as Agaricus palmatus in 1785 by French botanist Jean Bulliard;{{cite book |author=Bulliard JBF. |url=https://archive.org/stream/herbierdelafranc193240bull#page/n47/mode/1up |title=Herbier de la France |publisher=Paris, Chez l'auteur, Didot, Debure, Belin |year=1785 |location=France |page=plate 216}} mycologist Elias Magnus Fries later included it under the same name in his Systema Mycologicum.{{cite book |author=Fries E. M. |url=http://www.librifungorum.org/Image.asp?ItemID=21&ImageFileName=0186b.jpg |title=Systema Mycologicum |publisher=Lundae: Ex officina Berlingiana |year=1821 |page=186 |language=la |access-date=2009-09-11 |archive-url=https://web.archive.org/web/20201021105057/http://www.librifungorum.org/Image.asp?ItemID=21&ImageFileName=0186b.jpg |archive-date=October 21, 2020 |url-status=usurped}} It was transferred to the then newly described genus Rhodotus in a 1926 publication by French mycologist René Maire.{{cite journal |author=Maire R. |year=1926 |title=Mycological studies |journal=Bulletin de la Société Mycologique de France |language=fr |volume=40 |issue=3 |pages=293–317}} French botanist Claude Gillet called the species Pleurotus subpalmatus in 1876.{{cite book |author=Gillet C. C. |url=https://books.google.com/books?id=ZIY5AAAAMAAJ&q=%22Claude%20Casimir%20Gillet%22&pg=PA343 |title=Les Hyménomycètes ou Description de tous les Champignons (Fungi) Qui Croissent en France |publisher=CH Thomas |year=1874 |location=Alençon |page=343}} A 1986 paper established Rhodotus palmatus as synonymous with Pleurotus pubescens (first described by American mycologist Charles Horton Peck in 1891).{{cite journal |author=Redhead SA. |year=1986 |title=Mycological observations 15–16: On Omphalia and Pleurotus |journal=Mycologia |volume=78 |issue=4 |pages=522–28 |doi=10.2307/3807763 |jstor=3807763}}{{cite journal |author=Peck CH. |year=1891 |title=Report of the State Botanist (1890) |journal=Annual Report of the New York State Museum |volume=44 |page=18 |issn=1066-9639 |oclc=6435019}} According to the same publication, another synonym is Lentinula reticeps, described by William Alphonso Murrill in 1915, who thought it to be synonymous with Agaricus reticeps (described by Montagne in 1856), A. reticulatus (Johnson, 1880), A. alveolatus (Cragin, 1885), Pluteus alveolatus (Saccardo, 1887), and Panus meruliiceps (Peck, 1905).{{cite journal |author=Murrill WA. |year=1915 |title=Notes on Agaricus reticeps Mont |journal=Mycologia |volume=7 |issue=5 |pages=290–92 |jstor=3753427}}

The placement of Rhodotus in the order Agaricales is uncertain, and various authors have offered solutions to the taxonomic conundrum. In 1951, Agaricales specialist Rolf Singer placed Rhodotus in the Amanitaceae because of similarities between the tribes Amaniteae and Rhodoteae, such as spore color and ornamentation (modifications of the spore wall that result in surface irregularities), structure of the hyphae and trama, and chlamydospore production during culture growth.{{cite journal |author=Singer R.|year=1951|title=The Agaricales in Modern Taxonomy|journal=Lilloa|volume=22|pages=1–832}}

File:Rhodotus palmatus 46170 crop.jpg

In 1953, French mycologists Robert Kühner and Henri Romagnesi placed Rhodotus in the family Tricholomataceae—a traditional "wastebasket taxon"—on the basis of spore color.{{cite book|title=Flore analytique des champignons supérieurs (agarics, boletes, chanterelles)|vauthors=Kühner R, Romagnesi H |year=1953|publisher=Masson et Cie|location=Paris |page=554|language=fr}} In 1969, Besson argued for the placement of Rhodotus with the Entolomataceae after studying the ultrastructure of the spores.{{cite journal|author=Besson M.|year=1969|title=Structure de la paroi sporique de Rhodocybe, Rhodotus et Clitopus (Agaricales) [Structure of spore wall of Rhodocybe, Rhodotus and Clitopilus (Agaricales)]|journal=Comptes rendus de l'Académie des sciences |series=Série D|volume=269|issue=2|pages=142–45|language=fr}} By 1986, Singer had revised the placement of Rhodotus in his latest edition of The Agaricales in Modern Taxonomy, noting that "It has formerly been inserted in the family Amanitaceae but is obviously closer to tribus Pseudohiatuleae of the Tricholomataceae."Singer 1986, p. 441. Tribe Pseudohiatuleae included such genera as Flammulina, Pseudohiatula, Cyptotrama, and Callistodermatium.Singer 1986, pp. 433–35. In 1988, a proposal was made to split the Tricholomataceae into several new families, including a family, Rhodotaceae, to contain the problematic genus.{{cite journal|author=Korf RP.|year=1988|title=Reports (N.S. 1) of the Committee for Fungi and Lichens on Proposals to Conserve and/or Reject Names|journal=Taxon|volume=37|issue=2|pages=450–63|doi=10.2307/1222170|jstor=1222170}}

The use of molecular phylogenetics has helped to clarify the proper taxonomic placement of Rhodotus. Studies of the ribosomal DNA sequences from a wide variety of agaric fungi have corroborated Kühner and Romagnesi's placement of Rhodotus in the Tricholomataceae as then understood. A large scale phylogenetic analysis published in 2005 showed Rhodotus to be in the "core euagarics clade",{{cite journal|vauthors=Binder M, Hibbett DS, Larsson KE, Larsson E, Langer E, Langer G |year=2005|title=The phylogenetic distribution of resupinate forms across the major clades of mushroom-forming fungi (Homobasidiomycetes)|journal=Systematics and Biodiversity|volume=3|issue=2|pages=113–57|doi=10.1017/S1477200005001623|bibcode=2005SyBio...3..113B |s2cid=13102957}} a name given to a grouping of gilled mushrooms corresponding largely to the suborder Agaricineae as defined by Singer (1986), but also including taxa that were traditionally classified in the Aphyllophorales (e.g., Clavaria, Typhula, Fistulina, Schizophyllum, etc.) and several orders of Gasteromycetes (e.g., Hymenogastrales, Lycoperdales, Nidulariales).{{cite journal|vauthors=Moncalvo JM, Vilgalys R, Redhead SA, Johnson JE, James TY, Catherine AM, Hofstetter V, Verduin SJ, Larsson E, Baroni TJ, Greg Thorn R, Jacobsson S, Clémençon H, Miller OK |title=One hundred and seventeen clades of euagarics|journal=Molecular Phylogenetics and Evolution|volume=23|issue=3|pages=357–400|year=2002|pmid=12099793|doi=10.1016/S1055-7903(02)00027-1|bibcode=2002MolPE..23..357M |url=http://www.botany.utoronto.ca/faculty/moncalvo/117clade.pdf|archive-date=2007-10-25 |archive-url=https://web.archive.org/web/20071025215852/http://www.botany.utoronto.ca/faculty/moncalvo/117clade.pdf}} These results corroborated a previous study which showed Rhodotus to be part of a clade containing species such as Cyptotrama asprata, Marasmius trullisatus, Flammulina velutipes, Xerula furfuracea, Gloiocephala menieri, and Armillaria tabescens.{{cite journal|vauthors=Moncalvo JM, Lutzoni FM, Rehner SA, Johnson J, Vilgalys R |year=2000|title=Phylogenetic relationships of agaric fungi based on nuclear large subunit ribosomal DNA sequences|journal=Systematic Biology|volume=49|issue=2|pages=278–305|doi=10.1093/sysbio/49.2.278|pmid=12118409|doi-access=}} The genera containing these latter species have been reassigned to the family Physalacriaceae; as of 2009, both Index Fungorum and MycoBank also list Rhodotus as belonging to the Physalacriaceae.{{cite web |url=http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=200961|title=Rhodotus palmatus – Index Fungorum Names record|publisher=CAB International|access-date=2009-06-12}}{{cite web|url=http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=18472|title=Rhodotus Maire 1926|publisher=MycoBank|access-date=2009-09-11}} Follow up molecular genetics surveys of Physalacriaceae fungi in China identified Rhodotus asperior as the second member of the Rhodotus genus.{{Cite journal |last1=Tang |first1=Li-Ping |last2=Hao |first2=Yan-Jia |last3=Cai |first3=Qing |last4=Tolgor |first4=Bau |last5=Yang |first5=Zhu L. |date=2014 |title=Morphological and molecular evidence for a new species of Rhodotus from tropical and subtropical Yunnan, China |url=https://doi.org/10.1007/s11557-013-0890-x |journal=Mycological Progress |language=en |volume=13 |issue=1 |pages=45–53 |doi=10.1007/s11557-013-0890-x |bibcode=2014MycPr..13...45T |s2cid=255313707 |issn=1861-8952}}

The specific epithet is derived from the Latin palmatus, meaning "shaped like a hand"—possibly a reference to the resemblance of the cap surface to the lines in the palm of a hand.{{cite book |author=Findlay WPK. |url=https://books.google.com/books?id=tJY_AAAAYAAJ&q=Rhodotus+palmatus |title=Wayside and Woodland Fungi |publisher=F. Warne |year=1967 |isbn=0-7232-0008-4 |location=London |page=130}}{{cite journal |author=Gaag H van der. |year=2007 |title=Rhodotus palmatus: the lonely mushroom |url=http://www.namyco.org/images/pdf%20files/Henk_article.pdf |url-status=dead |journal=McIlvainea |volume=17 |issue=1 |pages=7–8 |archive-url=https://web.archive.org/web/20110720025624/http://www.namyco.org/images/pdf%20files/Henk_article.pdf |archive-date=2011-07-20}} Common names for R. palmatus include the netted rhodotus,{{cite web |title=Fungi of Iowa: Rhodotus palmatus (Bull.: Fr.) Maire |url=http://www.herbarium.iastate.edu/fungi/fungispecies.php?sp=Rhodotus%20palmatus%20(Bull.:%20Fr.)%20Maire |url-status=dead |archive-url=https://web.archive.org/web/20110719210840/http://www.herbarium.iastate.edu/fungi/fungispecies.php?sp=Rhodotus%20palmatus%20%28Bull.%3A%20Fr.%29%20Maire |archive-date=2011-07-19 |access-date=2009-06-13 |publisher=Iowa State University of Science and Technology}} the rosy veincap,{{cite book |title=A Field Guide to Mushrooms, North America |vauthors=McKnight VB, McKnight KH |publisher=Houghton Mifflin Harcourt |year=1987 |isbn=0-395-91090-0 |location=Boston |page=Plate 19}} and the wrinkled peach.{{cite web |author=Holden, EM |year=2003 |title=Recommended English Names for Fungi in the UK: Report to the British Mycological Society, English Nature, Plantlife, and Scottish Natural Heritage |url=http://www.plantlife.org.uk/uploads/documents/recommended-english-names-for-fungi.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130302235323/http://www.plantlife.org.uk/uploads/documents/recommended-english-names-for-fungi.pdf |archive-date=2013-03-02 |access-date=2011-12-17 |publisher=Plantlife}}

{{Multiple image

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| image1 = Rhodotus palmatus5gills.jpg

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| caption1 = Rolled-in cap margins and adnate gill attachment to the stem are typical characteristics.

| caption2 = Some short gills, called lamellulae, do not extend entirely from the cap edge to the stem.

| alt1 = A mushroom growing out of a log with its white stem greatly curved so that the yellow mushroom cap lies down, exposing the gills. Small yellow drops of liquid are visible on the stem.

| alt2 = A side view of a light-pink mushroom cap growing on the side of a tree, revealing gills of different lengths. Small drops of yellow liquid are visible on the stem.

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The fruit body of Rhodotus has a cap, and stem without a ring or volva. The cap initially assumes a convex shape before flattening somewhat with age, and typically reaches widths of {{convert|2|–|6|cm|in|sp=us|1}}.{{cite book|vauthors=Healy RA, Huffman DR, Tiffany LH, Knaphaus G |title=Mushrooms and Other Fungi of the Midcontinental United States (Bur Oak Guide)|publisher=University of Iowa Press|location=Iowa City|year=2008|page=157|isbn=978-1-58729-627-7}} The edges of the cap are rolled inwards,{{cite book|title=Flora Agaricina Neerlandica—3|vauthors=Bas C, Kuyper TW, Noordeloos ME, Vellinga EC, Van Crevel R, Van Os J |year=1995|publisher=CRC|page=175|url=https://books.google.com/books?id=NGGiXsS9eYwC&pg=PA175|isbn=978-90-5410-616-6}} and the cap surface typically has a conspicuous network of lightly colored ridges or veins that outline deep and narrow grooves or pits—a condition technically termed sulcate or reticulate. Between the ridges, the surface color is somewhat variable; depending on the lighting conditions experienced by the mushroom during its development, it may range from salmon-orange to pink to red. The texture of the cap surface is gelatinous, and the internal flesh is firm but rubbery, and pinkish in color.

The gills have an adnate attachment to the stem, that is, broadly attached to the stem along all or most of the gill width. The gills are thick, packed close to each other, with veins and color similar to, but paler than, the cap.{{cite book |url= |title=North American Mushrooms: A Field Guide to Edible and Inedible Fungi |vauthors=Miller HR, Miller OK |publisher=Falcon Guide |year=2006 |isbn=0-7627-3109-5 |location=Guilford, CT |page=155}} Some of the gills do not extend the full distance from the edge of the cap to the stem. These short gills, called lamellulae, form two to four groups of roughly equal length. The stem is {{convert|1.5|–|3.0|cm|in|1|abbr=on}} tall and {{convert|0.4|–|0.6|cm|in|2|abbr=on}} thick (usually slightly larger near the base), and may be attached to the underside of the cap in a central or lateral manner. Like the cap color, stem size is also affected by the type of light received during fruit body maturation.

In nature, Rhodotus palmatus is sometimes seen "bleeding" a red- or orange-colored liquid. A similar phenomenon has also been observed when it is grown in laboratory culture on a petri dish: the orange-colored drops that appear on the mat formed by fungal mycelia precede the initial appearance of fruit bodies. The mature fruit body will turn green when exposed to a 10% aqueous solution of iron(II) sulfate (FeSO₄), a common mushroom identification test known as iron salts.{{cite web |url=http://www.mushroomexpert.com/macrochemicals.html|title=Testing Chemical Reactions|author=Kuo M|publisher=MushroomExpert.Com|access-date=2009-09-14}}

In deposit, the spore color of Rhodotus palmatus has been described most commonly as pink,{{cite book|author=Arora D.|title=Mushrooms Demystified: a Comprehensive Guide to the Fleshy Fungi|publisher=Ten Speed Press|location=Berkeley, California|year=1986|page=[https://archive.org/details/mushroomsdemysti00aror_0/page/203 203]|isbn=0-89815-169-4|url-access=registration|url=https://archive.org/details/mushroomsdemysti00aror_0/page/203}}{{cite book |author=Jordan M. |url=https://books.google.com/books?id=ULhwByKCyEwC&pg=PA175 |title=The Encyclopedia of Fungi of Britain and Europe |publisher=David & Charles |year=1995 |isbn=0-7153-0129-2 |location=Newton Abbot |page=175}}{{Dead link|date=October 2023|bot=InternetArchiveBot|fix-attempted=yes}}{{cite web |url=http://www.mushroomexpert.com/rhodotus_palmatus.html |title=Rhodotus palmatus|author=Kuo M|publisher=MushroomExpert.com|access-date=2009-06-14}} but also as cream colored. Viewed microscopically, the spores of Rhodotus have a roughly spherical shape, with dimensions of 6–7.2 by 5.6–6.5 μm; the spore surface is marked with numerous wart-like projections (defined as verrucose), typically 0.5–0.7 μm long.{{cite journal|vauthors=Pegler DN, Young TW |year=1975|title=Basidiospore form in the British species of Clitopilus, Rhodocybe and Rhodotus|journal=Kew Bulletin|volume=30|issue=1|pages=19–32|doi=10.2307/4102870|jstor=4102870|bibcode=1975KewBu..30...19P }} The spores are non-amyloid—unable to take up iodine stain in the chemical test with Melzer's reagent.{{cn|date=January 2023}}

The spore-bearing cells, the basidia, are club-shaped and 4-spored, with dimensions of 33.6–43.2 by 5.6–8 μm. Although this species lacks cells called pleurocystidia (large sterile cells found on the gill face in some mushrooms), it contains abundant cheilocystidia (large sterile cells found on the gill edge) that are 27.2–48 by 4.8–8 μm in size. Clamp connections are present in the hyphae. The outer cellular layer of the cap cuticle is made of bladder-shaped, thick-walled hyphae, each individually supported by a small stalk that extends down into a "gelatinized zone".

Chlamydospores are asexual reproductive units made by some fungi that allow them to exist solely as mycelium, a process which helps them survive over periods unsuitable for growth;{{cite book|vauthors=Alexopoulos CJ, Mims CW, Blackwell M |title=Introductory Mycology|year=1996|pages=230–31|publisher=John Wiley and Sons|isbn=0-471-52229-5}} Rhodotus was shown experimentally to be capable of producing these structures in 1906. The chlamydospores of Rhodotus are thick-walled cells that develop from single hyphal compartments, and have dimensions of {{cvt|12|–|8|μm}} by {{cvt|8|–|6|μm}}.{{cite journal|author=Marryat DCE.|year=1908|title=Chlamydospore formation in the Basidiomycete Pleurotus subpalmatus|journal=New Phytologist|volume=7|issue=1|pages=17–22|doi=10.1111/j.1469-8137.1908.tb06067.x|doi-access=free}}

Rhodotus palmatus is saprobic, meaning it obtains nutrients from decomposing organic matter.{{cite book|title=Fungal Decomposition of Wood: Its Biology and Ecology|vauthors=Rayner AD, Boddy L |year=1988|publisher=John Wiley & Sons Inc|isbn=978-0-471-10310-3|page=396}} It grows scattered or clustered in small groups on rotting hardwoods, such as basswood, maple, and especially elm; in Europe it is known to grow on horse chestnut. The mushroom prefers low-lying logs in areas that are periodically flooded and that receive little sunlight, such as areas shaded by forest canopy. A pioneer species in the fungal colonization of dead wood, it prefers to grow on relatively undecayed substrates. It is often found growing on dark-stained wood, especially the dried-out upper parts of trunks that have lost their bark.{{cite journal|vauthors=Rayner AD, Hedges MJ |year=1982|title=Observations of the specificity and ecological role of Basidiomycetes colonizing dead wood|journal=Transactions of the British Mycological Society|volume=78|pages=370–73|doi=10.1016/S0007-1536(82)80027-2|issue=2}} R. palmatus tends to fruit in cooler and moister weather, from spring to autumn in the United States, or autumn to winter in Britain and Europe.

File:Rhodotus palmatus.jpg

Described as having a circumboreal distribution, R. palmatus has been reported from Iran,{{cite journal|author=Saber M.|year=1990|title=Contribution to the knowledge of Agaricales pleurotoid in habit in Iran|journal=Iranian Journal of Plant Pathology|volume=26|issue=1–4|pages=29–40}} Hungary,{{cite journal|author=Siller I.|year=1999|title=Rare macrofungi in the Kekes north forest reserve in the Matra mountains, Hungary|journal=Mikologiai Kozlemenyek|volume=38|issue=1/3|pages=11–24 |language=hu}} Italy,{{cite journal|vauthors=Migliozzi V, Coccia M |year=1998 |title=Fungi from lazio area. IX. 43–46|journal=Micologia Italiana|volume=27|issue=3|pages=25–36|language=it}} Poland,{{cite journal|vauthors=Bujakiewicz A, Nita J |year=2004|title=Żyłkowiec różowawy Rhodotus palmatus (Bull.: Fr.) R. Maire – mieszkaniec białowieskich ostępów|journal=Chrońmy Przyrodę Ojczystą|volume=60|issue=5|pages=82–85|language=pl}} Slovakia,{{cite journal|author=Ripkova S.|year=2003|title=New, rare and less known macromycetes in Slovakia I|journal=Czech Mycology |volume=55|issue=3–4|pages=187–200|doi=10.33585/cmy.55304}} Denmark, Sweden, Norway,{{cite journal |author=Vesterholt J.|year=2005|title=Notes on rare fungi collected in Denmark|journal=Svampe|volume=55|pages=24–38}} Germany,{{cite journal|author=Krieglsteiner GJ.|year=1979 |title=1st reports of Ascomycetes and Basidiomycetes in West Germany|journal=Zeitschrift für Mykologie|volume=45 |issue=1 |pages=35–44|language=de}} the area formerly known as the USSR, Korea,{{cite journal|doi=10.4489/MYCO.2006.34.2.056|vauthors=Han SK, Park YJ, Choi SK, Lee JO, Choi JH, Sung JM |year=2006|title=Some unrecorded higher fungi of the Seoraksan and Odaesan National Parks|journal= Mycobiology|volume=34|issue=2|pages=56–60|pmid=24039471|pmc=3769548}} Japan,{{cite journal |author=Redhead SA.|year=1989 |title=A biogeographical overview of the Canadian mushroom flora|journal=Canadian Journal of Botany|volume=67|pages=3003–62|doi=10.1139/b89-384|issue=10}} New Zealand,{{cite book |title=New Zealand Fungi: An Illustrated Guide|author=Stevenson G.|year=1994|publisher=Canterbury University Press|location=Christchurch, New Zealand|isbn=978-0-908812-29-5|page=56}} Canada,{{cite web |author=Kaminskyj S |title=Rhodotus palmatus |url=https://www.usask.ca/biology/fungi/genus_species_pages/rhodotus_palmatus.shtml |url-status=dead |archive-url=https://web.archive.org/web/20201029083548/https://www.usask.ca/biology/fungi/genus_species_pages/rhodotus_palmatus.shtml |archive-date=2020-10-29 |access-date=2009-06-14 |publisher=University of Saskatchewan}} and the eastern U.S., from Kansas to Virginia northward.{{Cite book |last=Audubon |title=Mushrooms of North America |publisher=Knopf |year=2023 |isbn=978-0-593-31998-7 |pages=453}}{{cite journal|author= Cooke WB.|year=1975|title=The 1970 Indiana foray|journal=Mycologia|volume=67|issue=5|pages=1065–71| jstor = 3758604|doi=10.1080/00275514.1975.12019846}} Although often described as "rare", a 1997 study suggests that it may be relatively common in Illinois.{{cite journal|vauthors=Sundberg WJ, Methven AS, Monoson HL |year=1997|title=Rhodotus palmatus (Basidiomycetes, Agaricales, Tricholomataceae) in Illinois|journal=Mycotaxon|volume=65|pages=403–10}} It has been suggested that an increase in the number of dead elms, a byproduct of Dutch elm disease, has contributed to its resurgence.{{cite journal|vauthors=Dobson FS, Hawksworth DL |year=1996|title=The Slapton fungal (including lichen) survey: inventorying and documenting changes in the Mycobiota|journal=Field Studies|volume=8|issue=4|pages=677–84|url=http://fsj.field-studies-council.org/media/342227/vol8.4_235.pdf|access-date=2009-09-22|issn=0428-304X}}

Light at the red end of the visible spectrum has been observed to be required for the development of R. palmatus fruit bodies, contrary to the typical requirement for blue light seen with many other mushroom species. Fruiting occurs in the presence of green, yellow or red light with wavelengths above 500 nm, but only when blue light (under 500 nm) is absent. Consequently, phenotypic variations observed in the field—such as size, shape, and cap color—may be influenced by differing conditions of light color and intensity. For example, specimens grown in the laboratory under green light had fruit bodies with short, straight stems and pale orange, large caps with well-developed ridges and pits, an appearance similar to specimens found in the field that were growing under a canopy of green leaves. Laboratory-grown specimens under amber light had bright orange, small caps with less pronounced reticulations; similarly, field specimens found in the fall, after the leaves had fallen, were more orange to orange-pink in color.{{cite journal|author1=Miller OK Jr |author2=Palmer JG |author3=Gillman LS. |year=1980|title=The fruiting and development of Rhodotus palmatus in culture|journal=Mycotaxon|volume=11|issue=2|pages=409–19}}

File:Rhodotus palmatus1.jpg

In the 1980s in Europe, increases in the levels of air pollution, as well as changing land use practices coincided with reports of declines in the populations of certain mushrooms. Consequently, a number of fungal conservation initiatives were started to better understand fungal biodiversity; as of October 2007, 31 European countries have produced fungal Red Lists of threatened species.{{cite book |title=Guidance for Conservation of Macrofungi in Europe|vauthors=Senn-Irlet B, Heilmann-Clausen J, Genny D, Dahlberg A |year=2007|publisher=European Council for the Conservation of Fungi|location=Strasbourg|url=http://www.wsl.ch/eccf/Guidance_Fungi.pdf|access-date=2009-09-13}} Rhodotus palmatus is a candidate species in over half of the European fungal Red Lists, and is listed as critically endangered, endangered, or near threatened (or the equivalent) in 12 countries.{{cite book |title=European Red List of endangered macrofungi: Red list candidates |author=Dahlberg A. |year=2007 |publisher=European Council for the Conservation of Fungi |format=Excel file |url=http://www.wsl.ch/eccf/candlist-subtotals.xls |access-date=2009-09-13}} In the Baltic countries Estonia, Latvia, and Lithuania, it is considered by the Environmental Protection Ministries (a branch of government charged with implementing the Convention on Biological Diversity) to be regionally extinct, reported as "extinct or probably extinct".{{cite book|author=IUCN East European Programme.|title=Environmental status reports|publisher=International Union for Conservation of Nature and Natural Resources|location=Cambridge|year=1991|page=198|isbn=2-8317-0161-9}} It was one of 35 fungal species to gain legal protection in Hungary in 2005, making it a fineable offense to pick them.{{cite journal|vauthors=Siller I, Dima B, Albert L, Vasas G, Fodor L, Pal-Fam F, Bratek Z, Zagyva I |year=2006|title=Vedett nagygombafajok Magyarorszagon|trans-title=Protected macrofungi in Hungary|journal=Mikologiai Kozlemenyek|volume=45|issue=1/3|pages=3–158|language=hu, en}}

File:Rhodotus palmatus 19775.jpg stages of development]]

Depending on the source consulted, the edibility of Rhodotus palmatus is typically listed as unknown or inedible.{{cite web |author=Phillips R |title=Rhodotus palmatus |url=http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~6742.asp |access-date=2009-06-14 |publisher=Rogers Plants Ltd}} The species has no distinguishable odor, and a "bitter" taste, although one early description referred to the taste as "sweet".

As part of a Spanish research study to evaluate the antimicrobial activity of mushrooms, R. palmatus was one of 204 species screened against a panel of human clinical pathogens and laboratory control strains. Using a standard laboratory method to determine antimicrobial susceptibility, the mushroom was shown to have moderate antibacterial activity against Bacillus subtilis, and weak antifungal activity against both Saccharomyces cerevisiae and Aspergillus fumigatus.{{cite journal |vauthors=Suay I, Arenal F, Asensio FJ, Basilio A, Cabello MA, Díez MT, García JB, del Val AG, Gorrochategui J, Hernández P, Peláez F, Vicente MF |year=2000 |title=Screening of basidiomycetes for antimicrobial activities |journal=Antonie van Leeuwenhoek |volume=78 |issue=2 |pages=129–39 |doi=10.1023/A:1026552024021 |pmid=11204765 |s2cid=23654559}}

{{Reflist|30em}}

• {{cite book |author=Singer R.|title=The Agaricales in Modern Taxonomy. 4th rev. ed|publisher=Koeltz Scientific Books|location=Koenigstein|year=1986|isbn=3-87429-254-1}}

{{Commons|Rhodotus palmatus}}

• [http://www.indexfungorum.org/Names/genusrecord.asp?RecordID=18472 Rhodotus] at Index Fungorum
• [http://www.ne.jp/asahi/mushroom/tokyo/tricholoma/rhodotus/hosianzutake-page.htm Picture of spores]

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Category:Fungi of Africa

Category:Fungi of Asia

Category:Fungi of Europe

Category:Fungi of New Zealand

Category:Fungi of North America

Category:Fungi of Oceania

Category:Inedible fungi

Category:Agaricales genera

Category:Physalacriaceae

Category:Fungi described in 1785

Category:Taxa named by René Maire

Category:Fungus species