Pholiota alnicola
Description
Pholiota alnicola is a widely distributed saprophyte found on hardwoods and conifers throughout North America. This species is a bit of an outcast compared to the majority of Pholiota, belonging to the subgenus Flammula. Unlike most others, P. alnicola lacks the characteristic pleurocystidia and scales on its cap.
This dull yellow mushroom has a convex cap measuring about 5 cm in diameter and has a stipe 4-8 cm long. The gills are a lighter yellow and attach to the stipe. The spores of P. alnicola are a dark rusty brown measuring 9×4 micrometers. Interestingly, its mycelium has high levels of antioxidant activity and its potential for dietary supplement production is being researched.
It grows solitary or more typically clustered on dead or dying decidous trees, such as alder or birch often in damp sites.
Common names: Alder Scalycap.
Mushroom Identification
Ecology
Saprobic; growing in clusters on the decaying wood of hardwoods and occasionally on the wood of conifers; late summer and fall (fall through spring in California); widely distributed in North America.
Cap
3-6 cm; convex, becoming broadly convex or nearly flat; slimy to sticky when fresh; yellow, becoming dark yellow and/or developing rusty or olive green shades; fairly smooth, but sometimes with fibers or tiny scales near the margin.
Gills
Attached to the stem; close; whitish or pale yellow at first, later becoming dirty brownish-yellow or rusty brown; at first covered by a quickly disappearing, whitish to yellowish partial veil.
Stem
4-8 cm long; up to 1 cm thick; pale yellow at the apex and overall when young, becoming brownish from the base up; with, at most, a ring zone resulting from the partial veil; often covered with fibers, but not truly scaly.
Flesh
Pale yellow.
Odor and Taste
Odor not distinctive or fragrant; taste bitter.
Spore Print
Rusty brown.
Microscopic Features
Spores 8-10 x 4-5.5 µ; smooth; elliptical; with an inconspicuous apical pore; somewhat dextrinoid. Pleurocystidia absent; cheilocystidia variously shaped, 22-46 x 3-6 µ. Cuticular elements subgelatinous, 2-4 µ wide. Clamp connections present.
Similar Species
Kuehneromyces mutabilis can be very similar, although its cap is usually two-toned. It also has a more obvious sign zone and a dark tan stem below the ring zone; its gills are ochraceous when young, becoming cinnamon at maturity.
History
Described in 1838 by the great Swedish mycologist Elias Magnus Fries, who gave it the name Agaricus alnicola, this saprobic mushroom species was transferred to the genus Pholiota in 1949 by German-born mycologist Rolf Singer, thus establishing its currently accepted scientific name.
Synonyms of Pholiota alnicola are many and various, as is so often the case with large and conspicuous mushrooms; they include Pholiota flavida, Agaricus alnicola Fr., Agaricus apicreus Fr., Flammula alnicola (Fr.) P. Kumm., Flammula apicrea (Fr.) Gillet, Dryophila alnicola (Fr.) Quél., Pholiota alnicola (Fr.) Singer, Pholiota aromatica P. D. Orton, and Pholiota apicrea (Fr.) M.M. Moser.
The generic name Pholiota means scaly, and the specific epithet alnicola is a reference to the Alder trees (Alnus species) upon which these mushrooms most commonly occur
Photo sources:
Photo 1 - Author: Hamilton (ham) (CC BY-SA 3.0)
Photo 2 - Author: Jerzy Opioła (CC BY-SA 4.0)
Photo 3 - Author: Jerzy Opioła (CC BY-SA 4.0)
Photo 4 - Author: Jimmie Veitch (jimmiev) (CC BY-SA 3.0)