Chalciporus piperatus
Description
Chalciporus piperatus (syn. Boletus piperatus, Suillus piperatus), is a small pored mushroom of the family Boletaceae found in mixed woodland in Europe and North America. It has been recorded under introduced trees in Brazil, and has become naturalized in Tasmania and spread under native Nothofagus cunninghamii trees. A small bolete, the fruit body has an orange-fawn cap with cinnamon to brown pores underneath, and a high thick stipe. The rare variety hypochryseus, found only in Europe, has yellow pores and tubes. It does not stain blue on bruising.
This mushroom grows alone, scattered, or gregariously in mixed woodland, primarily with conifers.
Chalciporus piperatus contains toxins and is usually considered inedible. It has been used as a condiment in many countries, with the Italian chef Antonio Carluccio recommending it be used only to add its peppery flavor to other mushrooms. Some recommend that it be well-cooked before consumption to minimize the risk of gastric symptoms, but the peppery taste is lost with cooking, and even more so by reducing it to a powdered form.
In addition, it can be dried and ground and used as a pepper-like condiment or eaten cooked by people who like hot chilies.
Common names: Peppery Bolete.
Mushroom Identification
Ecology
Mycorrhizal - primarily with conifers, but well documented under aspen and other hardwoods (Singer, 1986); growing alone, scattered, or gregariously; summer and fall; fairly widely distributed, but more common in northern and western North America.
Cap
2-7 cm; convex, becoming broadly convex; sticky when fresh, but soon dry; bald; shiny; dull reddish-brown to dull pinkish-tan, fading to tan.
Pore Surface
Beginning to run down the stem; cinnamon brown to reddish-brown, becoming dull coppery reddish at maturity; bruising dark rusty brown; usually with 1-2 pores per mm near the margin, but often with wide, angular pores near the stem that create fine lines at the stem apex; tubes to 5 mm deep.
Stem
2-5 cm long; 1-2 cm thick; more or less equal; dry; solid; colored like the cap; bald; base with bright to dull yellow mycelium.
Flesh
Yellowish to pinkish in the cap; brighter yellow in the stem; not staining on exposure, or staining slightly pinkish.
Odor and Taste
Odor not distinctive; taste strongly peppery.
Chemical Reactions
Ammonia grayish to olive on cap surface; negative to pinkish-gray on flesh. KOH negative to gray on cap surface; negative to gray on flesh. Iron salts negative on cap surface; negative on flesh.
Spore Print
Brown to reddish-brown.
Microscopic Features
Spores 7-11 x 3-4 µ; smooth; subfusoid; yellowish in KOH. Hymenial cystidia fusoid to fusoid-ventricose; to about 50 x 10 µ. Pileipellis a tangled layer of cylindric elements 5-12 µ wide; terminal elements with rounded to subacute apices; hyaline to yellowish.
Look-Alikes
-
Mycorrhizal with oaks; it has broadly ellipsoidal spores.
-
Much larger and has a reticulate stem; its pores become orange at maturity but they quickly turn blue when bruised.
-
Has a white cap and orange or red pores when mature; its flesh turns pale blue when cut and then fades back to its original pallid color.
-
Has brighter colors than C. piperatus, including completely red tubes.
History
French mycologist Pierre Bulliard described the species as Boletus piperatus in 1790. In its taxonomic history, it has been transferred to the genera Leccinum (Samuel Frederick Gray, 1821), Viscipellis (Lucien Quélet, 1886), Ixocomus (Quélet, 1888), Suillus (Otto Kuntze, 1898), and Ceriomyces (William Alphonso Murrill, 1909). It was reclassified and given its current binomial name in 1908 by Frédéric Bataille when he made it the type species of the newly circumscribed genus Chalciporus. The species name piperatus means "peppery" in Latin.
Chalciporus piperatus is a member of the genus Chalciporus, with which the genus Buchwaldoboletus form a group of fungi that is an early offshoot in the Boletaceae. Many members of the group appear to be parasitic.
Two varieties have been described. Chalciporus piperatus var. hypochryseus was originally described as Boletus hypochryseus by Czech mycologist Josef Šutara in 1993, and was moved to Chalciporus a year later by Regis Courtecuisse. Wolfgang Klofac and Irmgard Krisai-Greilhuber reclassified it as a variety of C. piperatus in 2006, although some sources continue to regard it as a distinct species.
Variety amarellus, first published by Quélet as Boletus amarellus in 1883 and later transferred to Chalciporus by Bataille in 1908, was described as a variety of C. piperatus in 1974 by Albert Pilát and Aurel Dermek.
Chalciporus piperatus Chemistry
Sclerocitrin, a pigment compound originally isolated from the common earthball (Scleroderma citrinum), is the major contributor to the yellow color of the mycelium and the stipe base of C. piperatus fruit bodies. Other compounds that have been isolated from this species include norbadione A, chalciporone, xerocomic acid, variegatic acid, variegatorubin, and another yellow pigment, chalcitrin. Chalciporone is responsible for the bitter taste of the fruit bodies. The pigments sclerocitrin, chalcitrin, and norbadione A are derived biosynthetically from xerocomic acid. Related compounds found in the fruit bodies include the chalciporone isomers isochalciporone and dehydroisochalciporone.
A field study of fungi growing in polluted sites in Czechia and Slovakia found that C. piperatus fruit bodies growing near lead smelters and on mine and slag dumps had the greatest ability to bioaccumulate the element antimony. In one collection, an "extremely high" level of the element was detected—1423 milligrams of antimony per kilogram of dried mushroom. In comparison, the antimony levels detected in other common terrestrial fungi from the same area, both saprobic and ectomycorrhizal, were more than an order of magnitude smaller.
Photo sources:
Photo 1 - Author: Holger Krisp (CC BY 3.0)
Photo 2 - Author: {{{2}}} (CC BY-SA 3.0)
Photo 3 - Author: thinker (CC BY-SA 3.0)
Photo 4 - Author: Mars 2002 (CC BY-SA 3.0)
Photo 5 - Author: Jörg Hempel (CC BY-SA 2.0)
