Lactarius vietus

Lactarius vietus was first described by Elias Magnus Fries in 1821 as Agaricus vietus in his Systema Mycologicum.{{cite web |url=http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=245540 |title=Agaricus vietus Fr., Syst. mycol. (Lundae) 1: 66 (1821) |publisher=CAB International |work=Index Fungorum |access-date=27 December 2010}}{{cite book |title=Systema Mycologicum |last=Fries |first=Elias Magnus |author-link=Elias Magnus Fries |year=1821 |publisher=Mauritius |location=Greifswald, Germany |page=[https://archive.org/details/bub_gb_Qj8-AAAAcAAJ/page/n147 66] |url=https://archive.org/details/bub_gb_Qj8-AAAAcAAJ |quote=vietus. |language=la}} In his 1838 work Epicrisis systematis mycologici, Fries reclassified the species as a Lactarius, giving it its current name.{{cite web |url=http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=200993 |title=Lactarius vietus (Fr.) Fr., Epicr. syst. mycol. (Upsaliae): 344 (1838) [1836-1838] |publisher=CAB International |work=Index Fungorum |access-date=27 December 2010}}{{cite book |title=Epicrisis Systematis Mycologici |last=Fries |first=Elias Magnus |author-link=Elias Magnus Fries |year=1838 |location=Uppsala, Sweden |publisher=Typographia Academica |page=[https://archive.org/details/bub_gb_kuIUAAAAYAAJ/page/n369 344] |url=https://archive.org/details/bub_gb_kuIUAAAAYAAJ |quote=Epicrisis systematis mycologici. |language=la}} Subsequent attempts to reclassify the species have been unsuccessful. In his 1871 work Der Führer in die Pilzkunde, Paul Kummer reclassified the species as a member of Galorrheus,{{cite web |title=Galorrheus vietus (Fr.) P. Kumm. 1871 |url=http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=507865 |publisher=International Mycological Association |work=MycoBank|access-date=29 December 2010}} and in Otto Kuntze's 1891 Revisio generum plantarum, the species was placed in the genus Lactifluus.{{cite web |title=Lactifluus vietus (Fr.) Kuntze 1891 |url=http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=231659 |publisher=International Mycological Association |work=MycoBank |access-date=29 December 2010}} Both Galorrheus vietus and Lactifluus vietus are now considered obligate synonyms (different names for the same species based on one type) of Lactarius vietus.{{cite web |title=Lactarius vietus (Fr.) Fr. 1838 |url=http://www.mycobank.org/MycoTaxo.aspx?Link=T&Rec=200993 |publisher=International Mycological Association |work=MycoBank |access-date=29 December 2010}} The specific epithet is from the Latin vietus, meaning shrunken.{{cite book |title=British Basidiomycetaceae: a Handbook to the Larger British Fungi |author=Rea, Carleton |author-link=Carleton Rea |year=1922 |publisher=Cambridge University Press |location=Cambridge, UK |pages=489–490 |url=https://www.biodiversitylibrary.org/page/17128324}} It is commonly known as the grey milkcap.

File:Lactarius spec. - Lindsey 19b.jpg

Lactarius vietus typically has a cap of {{convert|2.5|to|7.5|cm|in|sigfig=1}} across, with a flattened-convex shape.{{cite book |title= Complete Guide to British Mushrooms & Toadstools|author1=Sterry, Paul |author2=Hughes, Barry |year= 2009|publisher= HarperCollins|isbn= 978-0-00-723224-6|page= 52}} At times, the cap becomes widely funnel-shaped, and sometimes features a broad or pointed umbo, though the centre of the cap is typically depressed. The cap is coloured grey, sometimes with violet, flesh-coloured, pale yellowish-brown or red tints, though it is paler towards the cap margin in young mushrooms. Very pale specimens have also been recorded in the United States, though they are not true albinos. The cap's margin is curved inwards in younger specimens, and wavey. The cap surface is smooth, and can be slimey or sticky when wet. The stem measures {{convert|2.5|to|8|cm|in|sigfig=1}} by {{convert|2|to|7|cm|in|sigfig=1}}, and is generally cylindrical in shape. Sometimes the stem narrows downwards, or is club-shaped. In colour, the stem whitish or greyish, paler at the top, and is rather weak and easily broken. The flesh is a whitish-buff colour, and is often absent in the stem, leaving it hollow. The crowded gills can be decurrent (with the gill running down the stem) or adnate (with the entire depth of the gill connecting to the stem), and in colour are whitish to a dirty buff. They are thin and flaccid, and there are three to four tiers of lamellulae (short gills that do not reach the stem from the cap margin).{{cite journal |author= Smith, Alexander Hanchett |author-link= Alexander Hanchett Smith |year= 1977|title= Variation in two common North American Lactarii|journal= Kew Bulletin|volume= 31|issue= 3|pages= 449–453|issn= 0075-5974|doi=10.2307/4119385|jstor= 4119385}} The gills produce white milk, which dries a brownish or greenish grey after about 20 minutes.{{cite book |title=Mushrooms and Toadstools of Britain and Northern Europe |last=Kibby |first=Geoffrey |year=2003 |publisher=Hamlyn |isbn=978-0-7537-1865-0 |page=183}} The mushroom flesh will slowly stain a greyish colour if a drop of FeSO₄ solution is applied to it as a chemical colour test.{{cite book |author1=Bessette, Arleen R. |author2=Bessette, Alan E. |author3=Harris, David B. |title=Milk Mushrooms of North America: A Field Guide to the Genus Lactarius |publisher=Syracuse University Press |location=Syracuse, New York |year=2009 |page=262 |isbn=978-0-8156-3229-0}}

The spore print is typically a creamy white, with a slight salmon tinge, but it has been observed to vary from white to yellow depending on the density, meaning that it is not a useful means of identification. Individual spores are a buff-white, amyloid (staining blue in Melzer's reagent) and hyaline.{{cite book |author1=Fischer, David Hackett |author2=Bessette, Alan |author3=Bessette, Arleen R. |title=Mushrooms of Northeastern North America |publisher=Syracuse University Press |location=Syracuse |year=1997 |isbn=978-0-8156-0388-7}} In shape, the spores are elliptic, with a moderately well-developed network of ridges, measuring between 8 and 9.5 by 6.5 to 7.5 micrometres (μm).{{cite book |title= Mushrooms and Other Fungi of Great Britain and Europe|last= Phillips|first= Roger|year= 1981|publisher= Pan Books|location= London|isbn= 0-330-26441-9|page=87}} The pleurocystidia (cystidia on the face of the gills) are shaped like narrow spindles, typically measuring between 40 and 75 μm long, but sometimes reaching 86 μm in length, by 6 and 11 μm wide at the widest point. The cheilocystidia (cystidia on the edge of the gills) are leaf or spindle shaped, measuring between 30 and 52 μm long by 4 to 7 μm wide. The basidia are four-spored and club-shaped, measuring between 36 and 42 μm in length by 8 and 12 μm wide.

Lactarius uvidus is similar in appearance. In colour, it is a pale pink-buff, and its flesh turns a violet-lilac colour when cut. The white milk has a mild taste. Lactarius mammosus, a species described by Fries but not often mentioned by the mycological community for some time after his death, is also similar. Meinhard Moser, examining the identity of L. mammosus, concluded that it "is certainly more closely related to L. vietus than to L. fuscus,

but differs in habit and colour. The spores are slightly longer and the sculptures are less pronounced in L. vietus."{{cite journal |last1= Moser|first1= Meinhard|year= 1977|title= The problem of Lactarius mammosus Fr.|journal= Kew Bulletin|volume= 31|issue=3 |pages= 529–532|issn= 0075-5974|doi=10.2307/4119398|jstor= 4119398}}

Lactarius vietus milk has a very hot taste, and the mushroom lacks a distinctive smell. Although described by many mycologists as inedible,{{cite book |title=The Encyclopedia of Fungi of Britain and Europe |author=Jordan, Michael |author-link=Michael Jordan (mycologist) |year=2004 |publisher=Frances Lincoln |isbn=978-0-7112-2378-3 |page=310}} David Pegler claims that its acrid taste can be removed after boiling, allowing it to be consumed.{{cite book |title= Mushrooms and Toadstools|last= Pegler|first= David N.|year= 1983|publisher= Mitchell Beazley Publishing|location= London|isbn= 0-85533-500-9|page= 98}} Though the strong, acrid taste is a defining feature of the species, it is weaker or even absent in some older mushrooms, which is not unusual for Lactarius species. Occasionally, however, mushrooms of the species have been collected which have a mild taste; this has also been observed in other species with typically acrid tastes.

Lactarius vietus is fairly common, and can be found growing in moist areas under trees in autumn, often among Sphagnum moss. Though it strongly favours birch, it has also been found under oak.{{cite journal |title=Fungus associates of ectotrophic mycorrhizae |author=Trappe, James M. |volume=28 |issue=4 |journal=Botanical Review |year=1962 |pages=538–606 |issn= 0006-8101 |doi=10.1007/BF02868758|s2cid=42698903 }} It forms an ectomycorrhizal relationship with the trees under which it grows.{{cite book |author1=Rotheroe, Maurice |author2=Moore, David Scott |author3=Nauta, Marijke M. |author4=Evans, Shelley |title=Fungal Conservation: Issues and Solutions (British Mycological Society Symposia) |publisher=Cambridge University Press |year=2008 |page=140 |isbn=978-0-521-04818-7 }} It can also be found growing on rotting wood or other hard surfaces; specimens have been observed on both conifer and hardwood logs. These are typically smaller specimens, and it is possible that they represent a dwarf variety. Despite growing on rotting wood, the species is not saprotrophic; instead, the mycelia of the species are linking with tree roots growing through or near the wood. This is a particularly useful adaptation when the soil is either wet or nutrient-poor.{{cite book |last1=Verbeken |first1=A. |last2=Mueller |first2=G. M. |editor1-first=Roy |editor1-last=Watling |title=Tropical Mycology |year=2002 |publisher=CAB International |isbn=978-0-85199-542-7 |pages=11–24 [15] |chapter=Diversity and ecology of tropical ectomycorrhizal fungi in Africa}} Mushrooms can sometimes grow in large numbers,{{cite book |author=Pegler, David N. |title=Field Guide to the Mushrooms & Toadstools of Britain and Europe |publisher=Kingfisher |page=118 |year=1990 |isbn=0-86272-565-8}} but they can also be found growing in tight clumps, or solitarily when growing out of season. The species can be found in Europe, with collections in Scandinavia, the British Isles Bulgaria,{{cite journal |title=On the chemical composition of some mushrooms of the genera Lactarius and Tricholoma distributed in Bulgaria |journal=Naui. Trudove Viss Sel.-stop. Inst. "V. Kolarov" |year=1969 |author1=Stefanov, S. |author2=Zaprianov, J. |volume=18 |issue=4 |pages=57–59 |language=bg}} Germany,{{cite journal |last1=Straus |first1=Adolf |year=1969 |title=Pilzfunde im Gebiet des Naturschutzgebietes Krumme Laake bei Berlin-Rahnsdorf und seiner Umgebung |language=de |journal=Willdenowia |volume=5 |issue=2 |pages=171–179}} and northern Turkey;{{cite journal |title=Determination of some trace metals of mushrooms produced in middle Black Sea region of Turkey |journal=Fresenius Environmental Bulletin |last1=Turhan |first1=Kadir |year=2007 |volume=16 |issue=4 |pages=397–402 }} in North America, it has been recorded as common in Canada and both the northern and southern United States;{{cite journal |last1=Calkins |first1=W. W. |year=1887 |title=Notes on Florida Fungi. No. 16 |journal=Journal of Mycology |volume=3 |issue=7 |page=82 |doi=10.2307/3752534|jstor=3752534 }} in northern Asia, it was found in regions near both the Oka River{{cite journal |title=The occurrence of mycorrhizal fungi in the Oka River forest reserve |journal=Mikologiya i Fitopatologiya |author=Burlova, L. G. |volume=22 |issue=3 |pages=199–202 |language=ru |issn=0026-3648}} and the central Angara River in Siberia;{{cite journal |title=Consortive relations in wood-decomposing fungi in the central Angara river area Russian SFSR USSR |journal=Mikologiya i Fitopatologiya |author=Astapenko, V. V. |year=1990 |volume=24 |issue=4 |pages=289–298 |language=ru}} and in eastern Asia, it has been collected in China.{{cite book |title=The Macrofungus Flora of China's Guangdong Province |last=Bi |first=Zhishu |author2=Zheng, Guoyang |author3=Li, Taihui |year=1993 |publisher=Chinese University Press |isbn=978-962-201-556-2 |page=506 |url=https://books.google.com/books?id=0cAered-vqYC&q=%22lactarius+vietus%22&pg=PA506}}

• List of Lactarius species

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• [https://web.archive.org/web/20110929105152/http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~6366~gid~~source~gallerydefault.asp Lactarius vietus] at RogersMushrooms

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vietus

Category:Fungi described in 1821

Category:Fungi of North America

Category:Fungi of Europe

Category:Fungi of Asia

Category:Edible fungi

Category:Taxa named by Elias Magnus Fries

Category:Fungus species