Trametes betulina
Description
Trametes betulina (formerly Lenzites betulina) produces small to medium-sized (2 – 10cm), semicircular brackets on dead wood. These brackets often appear in overlapping clusters, but I find there is usually space between the mushrooms horizontally. As a result, the mushrooms only rarely fuse laterally.
L. betulina grows outward from a central point of attachment, so its final shape will depend on how much space it has to grow. When fruiting from the side of a log, the mushrooms will grow into a semicircular shape. If the mushroom began on top of a log (which is not as common), it will become kidney-shaped to almost circular and may develop a rudimentary stipe-like structure. L. betulina can grow up to 2cm thick at the point of attachment.
The species is saprobic on the deadwood of hardwoods. Annual; growing singly or in overlapping groups on logs (hardwoods and coniferous woods); producing a white to straw-colored rot of the sapwood.
Common names: Gilled Polypore, Birch Mazegill, Multicolor Gill Polypore.
Mushroom Identification
Ecology
Saprobic on the deadwood of hardwoods and, occasionally, conifers (originally named betulina by Fries, in Sweden, based on its association with birch-demonstrated in Irene Andersson's photo of the species in Sweden-but later discovered to be cosmopolitan in its host preferences); annual; growing alone or in overlapping clusters on logs and stumps; producing a white to straw-colored rot of the sapwood; summer and fall; widely distributed in North America.
Cap
Up to 10 cm across and 2 cm thick; semicircular, irregularly bracket-shaped, or kidney-shaped; flattened-convex; densely hairy, with concentric zones of texture; often radially bumpy or ridged; with zones of whitish, grayish, and brownish colors; flexible; without a stem; sometimes developing greenish colors in old age as a result of algae.
Gills
Whitish; well-spaced or fairly close; sharp; tough; up to 1 cm or deeper.
Flesh
White; extremely tough and corky.
Spore Print: White.
Trametes betulina Similar Species
From above, L. betulina is nearly indistinguishable from the Turkey Tail. However, I find I can usually identify L. betulina without having to look at the gills (at least in my part of the world). In my experience, L. betulina is usually larger and thicker than the Turkey Tail. Additionally, its cap more frequently features orange colors and usually features larger sections of pale colors than that of T. versicolor.
Perhaps most helpfully, fresh L. betulina mushrooms have a flat cap that is often slightly curved up around the edges. The Turkey Tail is also flattish but often curves downward. L. betulina can curve down when dried out, but this is more dramatic than the downward curve of a dried-out T. versicolor. These differences are very subtle, so the best way to consistently tell the difference is to look at lots of samples of both mushrooms.
There are a few other mushrooms that have well-defined gills. The ones most likely to be confused with L. betulina belong to the genus Gloeophyllum. Generally, these mushrooms are much darker in color. They tend to have brown flesh and brown gills.
Medicinal Properties
The [url=https://pubmed.ncbi.nlm.nih.gov/25271861/]anticancer properties, antibiotic activity, and chemical composition of Trametes betulina ethanol extract (EE) were evaluated. Eight compounds including 5 sterols were isolated from L. betulina, and 7 compounds were isolated from L. betulina for the first time. The EE displayed strong anticancer activity against tumor cell line MDA-MB-231, with a half maximal inhibitory concentration of 51.46 μg/mL, and there was 83.15% inhibition at a concentration of 200 μg/mL (MTT assay). The antimicrobial activity of the EE was evaluated against 6 microorganisms-Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Fusarium graminearum, Gibberella zeae, and Cercosporella albo-maculans-and the EE showed moderate antibiotic activity.
History
In 1753, when Carl Linnaeus described this bracket fungus, he gave it the binomial scientific name Agaricus betulinus. The great Swedish mycologist Elias Magnus Fries transferred this species to the genus Lenzites in 1838, and Lenzites betulinus is still generally-accepted scientific name today.
Lenzites betulinus has several synonyms including Agaricus betulinus L., Agaricus flaccidus Bull., Daedalea variegata Fr., Apus coriaceus Gray, Daedalea betulina (L.) Fr., Lenzites flaccida (Bull.) Fr., and Lenzites variegata (Fr.) Fr.
Lenzites, the genus name, was established in 1835 by Elias Magnus Fries, perhaps honouring German mycologist Harald Othmar Lenz (1798 - 1870). The specific epithet betulinus means 'of birch trees' - a reference to the genus of host trees upon which this bracket fungus is most commonly found.
Photo sources:
Photo 1 - Author: Liz Popich (Lizzie) (CC BY-SA 3.0)
Photo 2 - Author: Ian Dodd (kk) (www.kundabungkid.com) Australia (kundabungkid) (CC BY-SA 3.0)
Photo 3 - Author: Ian Dodd (kk) (www.kundabungkid.com) Australia (kundabungkid) (CC BY-SA 3.0)
Photo 4 - Author: Wilhelm Zimmerling PAR (CC BY-SA 4.0)
