Gyroporus purpurinus

[ Basidiomycetes > Boletales > Gyroporaceae > Gyroporus . . . ]

by Michael Kuo

For some reason, this is one of those mushrooms I always want to find--and almost never can. I don't know how many times I have excitedly stooped down to pick it, only to discover that I am looking at one of several purplish Tylopilus species. Gyroporus purpurinus has yellowish spores, and therefore has a pore surface that eventually becomes pale yellow--while Tylopilus pore surfaces are typically pinkish by maturity.

Why I get so excited about Gyroporus purpurinus, I don't know. It's a tiny little purplish red bolete, and I frankly have real doubts about its status as a separate "species"; not a lot, other than the color, separates it from Gyroporus castaneus, which is much more common and which, as its name suggests, is brown. Neither testing chemical reactions nor microscopic analysis provides a better means of separating the two mushrooms than simply observing that one is purplish red and the other is brown.

Gyroporus purpurinus is edible.

Description:

Ecology: Mycorrhizal with hardwoods or pines; growing alone or scattered; summer and fall; east of the Rocky Mountains and in Mexico.

Cap: 2-8 cm; convex, becoming broadly convex or nearly flat in age; dry; smooth or slightly velvety; sometimes becoming slightly cracked in age (like me, according to my friends); purplish red.

Pore Surface: Whitish at first, becoming yellowish; not bruising; 1-4 pores per mm; tubes to 8 mm deep.

Stem: 3-6 cm long; .5-1 cm thick; more or less equal, sometimes tapering to apex; dry; brittle; hollowing; colored like the cap; not bruising; not reticulate.

Flesh: White; not staining on exposure.

Odor and Taste: Not distinctive.

Chemical Reactions: Not recorded in the literature. In my collections, one might as well say that just about everything is "negative": Iron salts negative on cap surface, negative to very pale orangish on flesh; KOH erasing some of the pigment on the cap surface, negative to grayish on flesh; ammonia negative on cap surface and flesh (see illustration). The only significant difference between these reactions and those recorded for Gyroporus castaneus is possibly found in the reaction of the cap surface to ammonia, which is "amber orange" for the latter species, according to the literature.

Spore Print: Yellow.

Microscopic Features: Spores 8-11 x 5-7 µ; smooth; elliptic to oval.

REFERENCES: (Snell, 1936) Singer, 1945. (Singer, 1945; Snell & Dick, 1970; Smith & Thiers, 1971; Smith, Smith & Weber, 1981; Arora, 1986; Phillips, 1991/2005; Lincoff, 1992; Both, 1993; Horn, Kay & Abel, 1993; Bessette, Roody & Bessette, 2000.) Herb. Kuo 09289620, 07230306, 06300709.

Further Online Information:

Gyroporus purpurinus in Smith & Thiers, 1971
Gyroporus purpurinus at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2003, August). Gyroporus purpurinus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/gyroporus_purpurinus.html