Pholiota aurivella, commonly known as the Golden pholiota, Golden Scalycap, or the Golden Fleece, is a saprobic, medium to a large mushroom that grows in clusters on decaying wood. It is characterized by a viscid/slimy, yellowish to tawny, rounded cap with appressed scattered spot-like scales; and a dry, scaly, ochre stem.[i]
This species was first described as Agaricus aurivellus in 1786 by the German mycologist August Johann Georg Karl Batsch. However, in 1888 another German naturalist, Paul Kummer, transferred this species into the new genus of Pholiota, establishing the use of its currently accepted scientific name.
The etymology of this specie’s name is relatively straightforward. The generic name Pholiota refers to the scaly nature of this specie’s cap. While the epithet aurivella means golden (“Aure”) fleece (“vell”).
Pholiota aurivella is mainly characterized by an orange-yellow, rounded cap that is sticky, with scattered, flattened, reddish-orange scales. And by a stalk that is cottony above and dry and scaly below a poorly developed ring. A word of caution, accurate identification of P. aurivella and its accurate separation from other Pholiota species requires microscopic analysis as Pholiota species are capable of sharing all observable macro- and microscopic features, with the exception of spore size.
Cap: The cap of this species measures 5 to 15 cm in diameter. It is broadly bell-shaped or convex becoming broadly umbonate or plane. The surface of the cap is slimy/viscid and is covered in appressed scales. These scales are large, flattened to slightly recurved, and triangular or can be spot-like. The scales may wear away or may even wash off in wet weather. The overall color of the cap is bright golden yellow to rusty brown to tawny; while the scales are a darker reddish brown color.
Flesh: The flesh of this mushroom is firm and yellow.
Gills: The gills of this species are adnate (broadly attached) and crowded. They are yellow in young specimens and reddish or rusty-brown in older specimens with developed spores.
Stem: The stem of Pholiota aurivella measures 5 to 10 cm in length and is approximately 0.5 to 1.5 cm in thickness. The stem is uniformly cylindrical and solid. The texture is dry and smooth/cottony above the annulus and fibrillose or scaly below it. The stem can vary in color, it may be yellow, pale yellow-brown, or maybe concolorous with the cap.
Veil & Ring: This species has a fibrous, whitish partial veil that commonly leaves behind a slight evanescent ring or a fibrillose zone on the upper stalk.
Spore: The spores of P. aurivella measure 8.5-10 by 5-6.5 µm. They are ellipsoidal, smooth, thick-walled (~0.25µ), and with a distinct apical germ pore. Spores stain a cinnamon-brown color when stained with potassium hydroxide (KOH). In Melzer’s Iodine reagent spores stain a darker reddish-tawny color. Slightly smaller and thick-walled chrysocystidia are often present.
Spore Print: Pholiota aurivella has a brown or reddish-brown spore print.
Edibility and Flavor: Although some mycological literature considers P. aurivella as an edible species, it is NOT RECOMMENDED to consume this mushroom. Additionally, the consumption of the soft, gooey textured flesh of this mushroom is reported to cause gastrointestinal upset.
Smell: No distinctive odor.
Habitat: This species grows gregarious on living trunks, large fallen branches, and dead stumps of deciduous and coniferous trees. They are most commonly seen in association with hardwoods such as maple, basswood, elm, sycamore, beech, and birch.
Range: Pholiota aurivella has a wide North American distribution. It can be found throughout Canada and the United States. In the US, it is distributed throughout New York, North Carolina, Tennessee, Michigan, Colorado, Illinois, Idaho, Washington, Oregon, and New Mexico. Specimens can also be found in mainland Europe and in England as well.
Fruiting Season: The fruiting season for this species spans summer, fall, and early winter. In North America, it is most commonly encountered from June to November.
Pholiota aurivella can easily be identified by its sticky, yellow to orange-brown cap decorated with darker scales, its pale yellow, scaly stem, its brown spores; its yellow fibrillose veil, and its association with deciduous and coniferous trees.
Unfortunately, several other mushrooms which are thought to be closely related but genetically distinct from this species also have very similar morphologic characteristics. As such, it is suggested that a microscope is used for analysis as spore morphology may be required for accurate and confirmatory identification of this and other Pholiota species.
Below are some differentiating characteristics of common look-a-like species:
- Pholiota adiposa (Fat Pholiota) – this hardwood loving species has gelatinous scales on its cap and stalk. It also has smaller spores which measure 5-6 × 3-4 microns.
- P. limonella (=P. squarroso-adiposa) – this indistinguishable species has narrower, smaller spores measuring 6.5-9.5 × 3.5-5.5 microns. It is more commonly found on hardwoods and has dry scales and forms large, dense clumps on alder and maple trees in Northwestern United States.
- Pholiota abietis – this species has dry scales, smaller spores, and pale brown immature gills
- P. hiemalis – this species is poisonous. It has a stem that is typically flaring at the base and has gelatinous scales below. Its gills have yellow edges when young. Found on logs of fir in late fall.
- P. Flammans (Flame Scale-cap) – this species has a brilliant yellow to orange-yellow color, it is usually smaller in size, fruits earlier in the year, and had dry, bent scales on the stem. Its gills also bruise brown when injured.
- Armillaria Mellea (Honey mushroom) – this species is similar but is more dull colored and has white spores.
- P. connata – this species has a thinly viscid stalk
- P. filamentosa – this species has a lemon-yellow to greenish-yellow cap and a thick, persistent annulus on the stalk. It is found in close association with conifers.
Toxicity of Pholiota aurivella [v]
As mentioned, Pholiota aurivella can cause gastrointestinal upset in susceptible individuals when consumed. The symptoms of GI upset are reported to be somewhat delayed and are characterized by abdominal cramping, diarrhea, nausea, and vomiting.
[i] McKnight, K. H., & McKnight, V. B. (1998). GOLDSKIN SCALECAP Pholiota aurivella In A Field Guide to Mushrooms, North America (pp. 270–271). Houghton Mifflin.
[ii] Lincoff, G. (1981). Golden Pholiota. In National Audubon Society Field Guide to North American mushrooms (pp. 712-7130). Knopf.
[iii] D. Arora (1986) Pholiota aurivella In “Mushrooms Demystified: A Comprehensive Guide to the Fleshy Fungi,” Ten Speed Press, Berkeley
[iv] Kuo, M. (2007, November). The genus Pholiota. Retrieved from the MushroomExpert