|pores on hymenium|
|cap is convex|
|hymenium is adnate|
|stipe is bare|
|spore print is olive-brown|
|ecology is mycorrhizal|
Boletus frostii, commonly known as Frost's bolete or the apple bolete, is a bolete, an edible mushroom. As a member of the Boletaceae family, this mushroom has tubes and pores instead of gills beneath its cap. It may be recognized by its dark red slimy or sticky cap, the network-like pattern of the stem, and the yellowish drops exuded on the pore surface during development. Typically found growing near hardwood trees, especially oak, it is distributed in the eastern United States, Mexico, and Costa Rica.
This species was originally described by J. L. Russell of Salem, Massachusetts, based on a specimen he found in Vermont in 1874; he named it after his friend, another amateur American mycologist, Charles Christopher Frost. Bodge made reference to this species in 1950 when addressing the Mycological Society of America, when he spoke about the role of the amateur mycologist in discovering new species:
They would have informed us all about the man Russell, who named a fine new bolete for his friend Frost, and about the man Frost, who names a fine new bolete for his friend Russell. Boletus Frostii and Boletus Russelli are mushrooms with character, even though they were described by amateurs.
William Murrill in 1909 called this species Suillellus frostii. It is commonly known as "Frost's bolete", or the "apple bolete". In Mexico, its vernacular name is panza agria, which translates to "sour belly".
The cap is hemispheric to convex, later becoming broadly convex to flat to shallowly depressed, with a diameter of 5–15 centimetres (2.0–5.9 in). The cap margin is curved inwards, although as it ages it may turn out and upwards. The surface is shiny, sometimes appearing finely areolate (having a pattern of block-like areas similar to cracked dried mud); it is sticky as a result of having a gelatinous pellicle (the outer layer of the cap), dark red initially but fading with age. The flesh is up to 2.5 centimetres (1.0 in) thick, pallid to pale yellow (lemon-yellow), but turning blue immediately upon exposure.
The tubes comprising the pore surface (the hymenium) are 9–15 mm deep, yellow to olivaceous yellow (mustard yellow), turning dingy blue when bruised. The pores are small (2 to 3 per mm) and round, and until old age a deep red color that eventually becomes paler. The pore surface is often beaded with yellowish droplets when young (a distinguishing characteristic) and readily stains blue when bruised. The stem is 4 to 12 centimetres (1.6 to 4.7 in) long, and 1 to 2.5 centimetres (0.4 to 1.0 in) thick at its apex; it is roughly equal in thickness throughout its length, or it may taper somewhat toward the top, though some specimens may appear swollen in the middle (ventricose). The stem surface is mostly red, or yellowish near the base; it has raised lines in the form of a net-like pattern, a condition known as reticulate. The spore print is olive-brown.
- Microscopic features
Other red-capped boletes include the poisonous Boletes B. flammans and B. rubeoflammeus; the former grows most commonly under conifers, the latter in association with hardwoods in eastern North America and southern Arizona.
Habitat and distribution
Boletus frostii grows solitarily or scattered on the ground under hardwood trees; it fruits in summer or early autumn. William Murrill noted its preference for growing in "thin oak woods, where the light is sufficient to enable grass to grow", and Alexander H. Smith mentioned its preference for growing in "thin, sandy soil under scrub oak." In the United States, it has been collected from Vermont, Connecticut, New York, New Jersey, Pennsylvania, District of Columbia, Tennessee and Indiana. It has also been collected in Costa Rica, where it associates with the tree species Quercus copeyensis, Q. costaricensis, Q. rapurahuensis, and Q. seemanii; in Mexico, it is often found under Madrone.
In 1910, Murrill wrote of this mushroom: "Usually viewed with suspicion because of its red hymenium, but its properties are not accurately known." Several authors have advised against consuming this species, due to its resemblance to other toxic red-capped bolete species. Despite this, Boletus frostii is edible, and David Arora mentions that it is commonly sold in farmers' markets in Mexico. Its taste and odor have been described as "pleasant", although the cuticle of the cap may taste acidic.
- ^ a b Weber NS, Smith AH. (1980). The Mushroom Hunter's Field Guide. Ann Arbor, Mich: University of Michigan Press. pp. 104–105. ISBN 0-472-85610-3. Google Books
- ^ Dodge BO. (1952). "The fungi come into their own". Mycologia 44 (3): 273–91.
- ^ a b c Murrill WA. (1909). "The Boletaceae of North America". Mycologia 1 (1): 4–18.
- ^ a b Phillips R. "Rogers Mushrooms | Mushroom Pictures & Mushroom Reference". Rogers Plants Ltd.. http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~5619.asp. Retrieved 2009-07-29.
- ^ a b c d Arora D. (1986). Mushrooms Demystified: a Comprehensive Guide to the Fleshy Fungi. Berkeley, Calif: Ten Speed Press. p. 529. ISBN 0-89815-169-4. Google Books
- ^ a b c d e Thiers HD, Smith AH. (1971). The Boletes of Michigan. Ann Arbor, Mich: University of Michigan Press. pp. 343–44. ISBN 0-472-85590-5. here
- ^ Halling RE, Muller GM. "Macrofungi of Costa Rica:Boletus frostii". New York Botanical Garden. http://www.nybg.org/bsci/res/hall/frostii.html. Retrieved 2009-07-29.
- ^ Murrill WA. (1910). "Poisonous mushrooms". Mycologia 2 (6): 255–64.
- ^ Bessette A, Miller OK Jr, Bessette AR, Miller HR. (1995). Mushrooms of North America in color: a Field Guide Companion to Seldom-Illustrated Fungi. Syracuse: Syracuse University Press. p. 385. ISBN 0-8156-2666-5. Google Books