Agaricus porphyrocephalus
Description
Agaricus porphyrocephalus is a rare the brown-fibered version of "Agaricus campestris," well-known on lawns and meadows in eastern North America.
The cap is white in color and covered with fine purple-brown radial fibrils. The gills are initially pink, and as the fruiting bodies mature, the detached gills turn brown. The stems are white and smooth with narrow, ring-shaped remnants of a partial veil. Stem is cylindrical or slightly inflated in the middle, then taper to a narrower base. The flesh turns light pink when cut open.
Psalliota porphyrea F.H. Møller is a synonym.
Mushroom Identification
Ecology
Saprobic; growing alone, scattered, or gregariously in meadows, fields, lawns, and grassy areas; fall; midwestern and eastern North America.
Cap
4–9 cm; convex, becoming broadly convex; dry; whitish to brownish underneath brown to grayish brown fibrils and scales; the young margin often adorned with hanging whitish remnants of the partial veil.
Gills
Free from the stem; crowded; short-gills frequent; whitish in buttons but soon pink, then maturing to dark brown; covered with a thin white partial veil when in the button stage.
Stem
3–6 cm long; 1–1.5 cm thick; more or less equal above a slightly tapered base; with a quickly collapsing whitish ring; whitish to brownish; bald or finely fibrillose.
Flesh
Whitish; not changing when sliced.
Spore Print
Dark brown.
Microscopic Features
Spores: 5.5–6.5 x 3.5–4.5 µm; ellipsoid; smooth; thick-walled; brown in KOH. Basidia 4-sterigmate. Pleurocystidia not found. Cheilocystidia not found. Pileipellis a cutis; elements 5–10 µm wide, smooth, hyaline to yellowish in KOH.
Similar Species
Agaricus augustus is similar but much bigger, the spores are slightly bigger and its slices smell like bitter almonds.
History
In 1950 Danish mycologist Frits Hansen Møller (1887 - 1962) first described this musnroom and give the scientific name Psalliota porphyrocephalus.
In 1952 Møller transferred this species to the genus Agaricus, establishing the currently accepted scientific name Agaricus porphyrocephalus.
The specific epithet porphyrocephalus means "with a purple head" - a reference to the purplish-brown cap scales.
Photo sources:
Photo 1 - Author: luisballester (CC BY-NC 4.0)
