What You Should Know
Phaeolus schweinitzii is a common polypore that parasitizes conifer trees. Around the bases of its victims, it produces medium-sized to large mushrooms in overlapping rosettes resembling haphazardly stacked dinner plates.
This mushroom is not edible but can be used for making dyes. There is a very interesting "subculture" of people who are interested in mushrooms and other fungi mainly because they can dye wool with them. Dyeing wool with fungi (probably lichens) is even mentioned in the Bible (Ezekiel 27:7).
The fruitbodies usually are terrestrial, forming one or more circular to irregularly shaped caps from a short, thick stipe, or with several caps forming a rosette; occasionally, it forms shelf-like fruit bodies on the sides of stumps and snags.
The upper surface is tomentose to hairy, sometimes zonate, light yellowish-brown to brownish orange near the margin and deep to dark brown toward the center, often with a pale edge when growing. The pores are circular to angular or labyrinthine and become tooth-like in age.
When fresh, they are greenish, yellowish, or orange-tinted and bruise brown, then become grayish to brownish in age. The yellowish-brown to reddish-brown flesh is soft and watery at first, then dry and brittle with age.
Other names: Dyer's Polypore, Dyer's Mazegill.
Phaeolus schweinitzii Mushroom Identification
Parasitic on the roots and heartwood of living conifers and saprobic on deadwood; causing a brown to reddish-brown cubical rot; annual; "especially common in old-growth timber with basal fire scars" (Gilbertson & Ryvarden, 1987); common on Douglas-fir in the West, white pine in eastern North America, and loblolly pine in the South; widely distributed throughout North America where conifers are present.
Usually with one to several loosely arranged, large lobes arising from a single stem-like structure that emerges from the ground, but occasionally infused, shelving brackets attached to the base of the tree.
7–30 cm across; more or less circular, semicircular, or broadly lobed in outline (more circular when terrestrial and more semicircular when on standing wood), flat or centrally depressed; dry; roughened; velvety, especially when young and along the margin, but sometimes becoming bald in old age; with concentric zones of color and texture; colors extremely variable, ranging from dark brown to rusty brown or olive-brown, with zones of yellow and/or olive, and a paler marginal zone which can be very bright yellow or orange when young; paler, velvety zones often bruising promptly brown.
Running down the stem; orange to bright yellow when young, becoming greenish-yellow to olive, and eventually brown; bruising promptly dark brown to nearly black; with 1–3 angular or almost slot-like pores per mm; tubes 1–7 mm deep.
Usually present as a more or less central structure; 2.5–5 cm long; 2–2.5 cm thick; brown and velvety below the pore surface; bruising darker brown.
Pale brown becoming rusty brown; fairly soft when young, becoming stringy and leathery; often appearing zoned.
Reported as whitish to yellowish.
Phaeolus schweinitzii Look-Alikes
The woolly velvet polypore, is quite similar and does grow from conifers, but it is smaller and thinner, and its pore surface is never greenish.
Fruits from hardwood trees and never from the ground.
The mustard-yellow polypore, also grows only from hardwood trees or, occasionally, from their roots. Identification could be an issue where hardwoods and pines grow near each other, so that it's not clear which tree’s roots the mushroom is coming from, but the shape of the margin is slightly different from that of dyer’s polypore.
Chicken-of-the-woods is yellower and fruits from hardwoods or from yews (which are indeed conifers but do not resemble the pines and Douglas-first dyer’s mushroom favors).
Can be misidentified as dyer’s mushroom, despite usually having a different “look”, in part because guidebooks often describe the spring chicken wrong. They say it closely resembles its relative, chicken-of-the-woods when the resemblance is somewhat distant. Keying the mushroom out usually yields an identification of dyer’s mushroom instead, because the two share several key characteristics. However, spring chicken only grows on hardwoods.
Phaeolus schweinitzii Taxonomy
The basionym of this species was established in 1821 by Swedish mycologist Elias Magnus Fries, who gave it the binomial scientific name Polyporus Schweinitzii. In 1900 the French mycologist Narcisse Theophile Patouillard (1854 - 1926) transferred this species to the genus Phaeolus, thus establishing its currently-accepted scientific name as Phaeolus schweinitzii.
Synonyms of Phaeolus schweinitzii include Polyporus schumacheri (Fr.) Pat., Hydnum spadiceum Pers., Polyporus schweinitzii Fr.,Polyporus herbergii Rostk., Polyporus spongia Fr.,Daedalea suberosa Massee, and Phaeolus spadiceus (Pers.) Rauschert.
Phaeolus schweinitzii is the type species of the genus Phaeolus, in which this is the only species known to occur in Britain.
Some authorities place the Phaeolus genus within the family Polyporacea, but here we follow the Kew/British Mycological Society taxonomic system which places Phaeolus and hence this species within the family Fomitopsidaceae.
Phaeolus schweinitzii Etymology
The generic name Phaeolus comes from the prefix Phae- meaning dusky or obscure, and olus which modifies the meaning to 'somewhat' - so fungi in this genus are described as 'somewhat dusky' or perhaps darkish. The specific epithet schweinitzii honours American botanist-mycologist Lewis David von Schweinitz (1780-1834), considered by some to be the founding father of North American mycological science.
The specimen shown on the left was photographed in southern Portugal in January when the fruitbody was dry and very light in weight. Two months later it was still intact but had turned black.
The common name Dyer's Mazegill comes from its use in dyeing yarn various shades of yellow, orange, and brown, depending on the age of the fruitbody and the type of metal used as a mordant to bind the dye molecules to the fibers of the fabric.
Photo 1 - Author: No machine-readable author provided. Bernypisa assumed (based on copyright claims). (Creative Commons Attribution-Share Alike 2.5 Generic, 2.0 Generic and 1.0 Generic)
Photo 2 - Author: Strobilomyces (Creative Commons Attribution-Share Alike 4.0 International)
Photo 3 - Author: Norbert Nagel (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 4 - Author: James Lindsey (Creative Commons Attribution-Share Alike 2.5 Generic)
Photo 5 - Author: Arto Kemppainen (Public Domain)