penny bun

Description:

Boletus edulis is a well known European bolete that grows under spruces and, depending on how the species is defined, other conifers and even hardwoods. It is a large mushroom with a greasy to tacky, bald, brown cap and a meaty, swollen stem that features fine reticulation. The pore surface is initially white, with "stuffed" pores--but as the mushroom matures the pores become more visible and the pore surface becomes greenish yellow. The flesh does not change color when the mushroom is sliced, and its surfaces do not bruise on handling. Whether or not Boletus edulis occurs in North America is up for debate. Mushrooms meeting the general description above can be found in diverse North American ecosystems. However, molecular research has begun to reveal potential differences in ostensibly identical "Boletus edulis" collections in North America and Europe--for example, see the preliminary survey of boletes by Binder & Hibbett (2004), in which "Boletus edulis" collections line up into clearly distinct groups (type the accession numbers into the search box at GenBank if you're interested in seeing where the collections were made). ( http://www.mushroomexpert.com/boletus_ed... )

Habitat:

location: North America, Europe edibility: Choice fungus colour: Brown normal size: over 15cm cap type: Convex to shield shaped stem type: Bulbous base of stem, Simple stem spore colour: Olivaceous habitat: Grows in woods, Grows on the ground Boletus edulis Bull. ex Fr. Steinpilz Cèpe de Bordeaux, Bolet comestible, Champignon polonais, King Bolete, Porcini, Cep or Penny Bun, Borowik prawdziwy. Cap 8–20(30)cm, brown often with a whitish bloom at first gradually lost on expanding leaving a white line at the margin, smooth and dry initially becoming greasy, in wet weather slightly viscid and polished. Stem 30–230 x 30–70(110)mm, robust, pallid with white net. Flesh white, unchanging, flushed dirty straw-colour or vinaceous in cap. Taste and smell pleasant. Tubes white becoming grey-yellow. Pores small and round, similarly coloured. Spore print olivaceous snuff-brown. Spores subfusiform, 14–17 x 4.5–5.5µ. Habitat coniferous, broad-leaved or mixed woodland. Season summer to late autumn. Common. Edible – excellent. Distribution, America and Europe. This fungus is perhaps the most important edible species, it can often be found on sale in continental markets. Commercially it is dried and used as flavouring for soups. Comment Var. aurantio-ruber Dick & Snell differs in its ferruginous-red cap, and pores staining yellow-olive when bruised ( http://www.rogersmushrooms.com/gallery/D... )

Notes:

--------------Bioactive compounds----------Boletus edulis fruit bodies contain about 500 mg of ergosterol per 100 g of dried mushroom. Ergosterol is a sterol compound common in fungi. Additionally, the fruit bodies have about 30 mg of ergosterol peroxide per 100 g of dried mushroom. Ergosterol peroxide is a steroid derivative with a wide spectrum of biological activity, including antimicrobial and anti-inflammatory activity, and cytotoxicity to various tumor cell lines grown in laboratory culture. ---------Phytochelatins give B. edulis resistance to toxic heavy metals like cadmium. The mushroom also contains a sugar-binding protein, or lectin, that has affinity for the sugars xylose and melibiose. The lectin is mitogenic—that is, it can stimulate cells to begin the process of cell division, resulting in mitosis. Further, the lectin has antiviral properties: it inhibits the human immunodeficiency virus enzyme reverse transcriptase.Other studies suggest that B. edulis also has antiviral activity against Vaccinia virus and tobacco mosaic virus grown in culture. Antiviral compounds from mushrooms are a subject of interest in biomedical research for their potential to advance the knowledge of viral replication, and as new drugs in the treatment of viral disease. -----The fruit bodies have a high antioxidative capacity, due probably to a combination of various organic acids (such as oxalic, citric, malic, succinic and fumaric acids), tocopherols, phenolic compounds and alkaloids; the highest antioxidant activity is in the mushroom caps. Furthermore, fruit bodies were determined to have 528 mg of the antioxidant compound ergothioneine per kilogram of fresh mushroom; this value was the highest among many food items tested in one study. Porcini were thought to have anti-cancer properties according to Hungarian research conducted in the 1950s, but later investigations in the United States did not support this (wikipedia)