| Phlegmacium ponderosum | |
|---|---|
| | |
| Scientific classification | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Agaricales |
| Family: | Cortinariaceae |
| Genus: | Phlegmacium |
| Species: | P. ponderosum |
| Binomial name | |
| Phlegmacium ponderosum (A.H.Sm.) Niskanen & Liimat. (2022) | |
| Synonyms | |
| |
| Phlegmacium ponderosum | |
|---|---|
| Gills on hymenium | |
| Cap is convex | |
| Hymenium is adnate | |
| Stipe is bare | |
| Spore print is yellow | |
| Ecology is mycorrhizal | |
| Edibility is not recommended | |
Phlegmacium ponderosum, also known as the Ponderous Cortinarius, is a large species of mushroom producing fungus in the family Cortinariaceae. [1]
It was described in 1939 by the American mycologist Alexander H. Smith who classified it as Cortinarius ponderosus. [2]
In 2022 the species was transferred from Cortinarius and reclassified as Phlegmacium ponderosum based on genomic data. [3]
The specific epithet ponderosum (originally ponderosus) is named for the Pinus ponderosa trees which Smith observed the mushrooms growing under. [2]
This mushroom is one of the largest mushrooms in the family Cortinariaceae, with a convex cap that ranges from 10–30 cm (4–12 in) [4] and becomes plane in age. It often has an olive metallic tinge, and the surface is viscid, often with small rusty brown scales. [4] The margin is ocher and remains inrolled until the mushroom is fully mature. The flesh of the mushroom is yellow-white, thick and firm, with a mild to sour odor. [4] The gills are rusty brown, adnate [4] and slightly decurrent. The stalk is 8–20 cm (3–8 in) thick, 4–10 cm wide, and bulbous at the base. [4] It has a slimy yellow universal veil, and the cortina leaves a rusty brown hairy area on the upper stalk. The spores are brown and elliptical. [4]
Its edibility is unknown, but it is not recommended due to its similarity to deadly poisonous species. [4]
Cortinarius infractus is a similar species that usually has a smaller cap. [4] Boletus edulis also has a thick stem.
Smith observed the mushrooms growing under Pinus ponderosa and Quercus (Oak) species near Cave City in Oregon and under Spruce trees near Crescent City, California. [2]