Neoboletus luridiformis, also previously known as Boletus luridiformis and (invalidly) as Boletus erythropus, is a fungus of the bolete family, all of which produce mushrooms with tubes and pores beneath their caps. It is found in Northern Europe and North America, and is commonly known as the scarletina bolete, for its red pores (yellow when young). Other common names is: red foot bolete, dotted stemmed bolete, dotted stem bolete.
|N. luridiformis, Ukraine|
(Rostk.) Gelardi, Simonini & Vizzini (2014)
|pores on hymenium|
|cap is convex|
|hymenium is adnate|
|stipe is bare|
|spore print is olive-brown|
|ecology is mycorrhizal|
|edibility: edible but not recommended|
Whilst edible when cooked properly, it can cause gastric upset if raw. Where the two species coincide it can be confused with the poisonous Rubroboletus satanas, which has a paler cap.
In 1796 Christian Hendrik Persoon described Boletus erythropus, deriving its specific name from the Greek ερυθρος ("red") and πους ("foot"), referring to its red-coloured stalk. During the next 200 years or so, this name was used extensively for the species which is the subject of this article, and which (as well as a red stalk) has red pores. Recently it was discovered however that Persoon's mushroom had orange pores, and was a different species (actually thought to be Suillellus queletii). So the use of this name for the red-pored mushroom was invalid.
In 1844 Friedrich Wilhelm Gottlieb Rostkovius independently defined the red-pored species under the name Boletus luridiformis. That is now the first valid description of the taxon and is the basis of the current name (the basionym). The significance of the epithet "luridiformis" is that it is similar to the previously known fungus Boletus luridus (now Suillellus luridus).
Genetic analysis published in 2013 showed that B. luridiformis and many (but not all) red-pored boletes were part of a dupainii clade (named for Boletus dupainii), well-removed from the core group of Boletus edulis and relatives within the Boletineae. This indicated that it needed to be placed in a new genus. It became the type species of the new genus Neoboletus in 2014.
To avoid confusion, the name Boletus erythropus should now be avoided if possible (though in theory it still has a legitimate meaning as whatever species Persoon originally intended). It is not a valid synonym of Neoboletus luridiformis, and that can be indicated by using the term sensu auct. in place of the author name (that is, Boletus erythropus sensu auct. = Neoboletus luridiformis (Rostk.) Gelardi, Simonini & Vizzini).
Neoboletus luridiformis is a large solid fungus with a bay-brown hemispherical to convex cap that can grow up to 20 cm (8 in) wide, and is quite felty initially. It has small orange-red pores that become rusty with age, and bruise blue to black. The tubes are yellowish-green, and become blue quickly on cutting. The fat, colourful, densely red-dotted yellow stem is 4–12 cm (2–5 in) high, and has no network pattern (reticulation). The flesh stains dark blue when bruised; broken, or cut. There is little smell. The spore dust is olive greenish-brown.
The similar Suillellus luridus has a network pattern on the stem, and seems to prefer chalky soil. Rubroboletus satanas also has a stem network, but a very-pale whitish cap. Rubroboletus pulcherrimus has a reticulate stipe, and is larger in size.
Distribution and habitatEdit
The fungus is common in Europe, growing in deciduous or coniferous woodland in summer and autumn. It is often found in the same places as Boletus edulis. It is also widely distributed in North America, and is especially common under spruce in its range from Northern California to Alaska. In Eastern North America it grows with both soft, and hardwood trees. It seems to prefer acid soils.
Toxicity and edibilityEdit
Mild tasting, Neoboletus luridiformis is edible after longer cooking (some literature recommends 20 minutes). It is commonly collected in several European countries.
When raw or insufficiently cooked it can cause gastric upset, for the same reason it is not recommended for drying. Caution is advised as it resembles other less edible blue-staining boletes, and should thus be avoided by novice mushroom hunters.[page needed]
- Liddell, Henry George & Robert Scott (1980). A Greek-English Lexicon (Abridged ed.). United Kingdom: Oxford University Press. ISBN 978-0-19-910207-5.
- Roger Phillips (1985). Mushrooms and other fungi of Great Britain and Europe. London: pan Books. p. 201. ISBN 978-0-330-26441-9.
- Knudsen, Thomas; Vesterholt, J., eds. (2018). Funga Nordica Agaricoid, boletoid, clavarioid, cyphelloid and gasteroid genera. Copenhagen: Nordsvamp. p. 218. ISBN 978-87-983961-3-0.
- Species Fungorum actually has a page for an 1801 use of the name Boletus erythropus for Suillellus queletii, see "Boletus erythropus sensu Persoon ..." Species Fungorum. Royal Botanic Gardens Kew. Retrieved 2020-05-31.
- "the Boletus erythropus page". Species Fungorum. Royal Botanic Gardens Kew. Retrieved 2020-05-30.
- "the Neoboletus luridiformis page". Species Fungorum. Royal Botanic Gardens Kew. Retrieved 2020-05-30.
- Nuhn ME, Binder M, Taylor AF, Halling RE, Hibbett DS (2013). "Phylogenetic overview of the Boletineae". Fungal Biology. 117 (7–8): 479–511. doi:10.1016/j.funbio.2013.04.008. PMID 23931115.
- Gelardi M, Simonini G, Vizzini A (October 17, 2014). "Nomenclatural novelties" (PDF). Index Fungorum (192).
- Roger Phillips (2006). Mushrooms. Pan MacMillan. ISBN 978-0-330-44237-4.
- Desjarind D.E; Wood M.G; Stevens F.A. (2015). California Mushrooms. The comprehensive identification guide. Portland, Oregon: Timber Press. p. 354. ISBN 978-1-60469-353-9.
- David Arora (1986). Mushrooms Demystified. Ten Speed Press. ISBN 978-0-89815-169-5.