| Leccinum scabrum | |
|---|---|
 | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Boletales |
| Family: | Boletaceae |
| Genus: | Leccinum |
| Species: | L. scabrum |
| Binomial name | |
| Leccinum scabrum | |
| Synonyms | |
| |
Leccinum scabrum | |
|---|---|
 | Pores onhymenium |
 | Cap isconvex |
 | Hymenium isadnate |
 | Stipe isbare |
 | Spore print isolive |
 | Ecology ismycorrhizal |
 | Edibility isedible |
Leccinum scabrum, commonly known as therough-stemmed bolete,scaber stalk, andbirch bolete, is a species of fungus in the familyBoletaceae, and was formerly classified asBoletus scaber.
The birch bolete is widespread in Europe, in theHimalayas in Asia, and elsewhere in theNorthern Hemisphere, occurring only inmycorrhizal association withbirch trees. This mushroom is also becoming increasingly common in Australia and New Zealand where it is likelyintroduced. It is anedible mushroom.
Thecap is 5–15 cm (2–6 in) wide. At first, it is hemispherical, and later becomes flatter. The skin of the cap is tan or brownish, usually with a lighter edge;[1] it is smooth, bald, and dry to viscid.[1]
The pores are whitish[1] at a young age, later gray. In older specimens, the pores on the pileus can bulge out, while around the stipe they dent in strongly. The pore covering is easy to remove from the skin of the pileus.
Thestipe is 5–15 cm (2–6 in) long and 1–3.5 cm (3⁄8–1+3⁄8 in) wide, slim, with white and dark to black flakes, and tapers upward.[1] The basicmycelium is white.
Theflesh is whitish, sometimes darkening following exposure.[1] In young specimens, the meat is relatively firm, but it very soon becomes spongy and holds water, especially in rainy weather. When cooked, the meat turns black.
Thespore print is brown.[2]
Several different species ofLeccinum mushrooms are found in mycorrhiza with birches, and can be confused by amateurs andmycologists alike.L. variicolor has a bluish stipe.L. oxydabile has firmer, pinkish flesh and a different pileus skin structure.L. melaneum is darker in color and has yellowish hues under the skin of the pileus and stipe.L. holopus is paler and whitish in all parts.
Leccinum scabrum is a European species that has beenintroduced to various areas of the world, mostly appearing in urban areas.[1] In New Zealand, it associates solely withBetula pendula.[3] In North America, it can be found from June to September, except on the West Coast, where it appears from September to November.[2]
It grows in association with birch.[2] It has been found in association with ornamental birch trees planted outside of its native range, such as inCalifornia.[4]
The birch bolete is edible but considered not to be worthwhile by some guides.[5] It can be cooked in various mushroom dishes.[6] It can also be pickled inbrine orvinegar. It is commonly harvested for food in Finland and Russia.[7]
A few reports in North America (New England and the Rocky Mountains) after 2009 suggest that Leccinums (birch boletes) should only be consumed with much caution.[8][9]
In Nordic countries all Leccinum species are considered likely poisonous unless cooked for at least 15-20 minutes.[10][11]
