Agaricus pocillator
Description
Agaricus pocillator, a woodland mushroom, is distributed through southeastern North America in ranges at least as far north as Illinois. It can be distinguished in the field by its dark center, its small, bulbous base, which stains yellow, and its relatively slight stature. A. pocillator is inedible, and several other yellow-staining Agaricus species are poisonous. Hikers are often warned to avoid eating it when spotted.
Agaricus pocillator Murrill belongs to A. sect. Xanthodermatei, is a well-known species in the southeastern United States characterized by its cup-like bulb stipe (Kerrigan 2016). During a survey of wild mushrooms in Veracruz State, Mexico, numerous Agaricus species were collected. The present study aims to describe A. pocillator as a new record species from Mexico based on both morphological characters and molecular data.
Mushroom Identification
Ecology
Saprobic; growing alone or gregariously under hardwoods and conifers in forests; summer and fall; the southeastern United States, north to the southern Appalachians.
Cap
3–7 cm; convex at first, becoming broadly convex in age; dry; grayish brown overall, with appressed, innate, brown fibrils over a pale background; often with a darker center; the margin not yellowing when rubbed repeatedly.
Gills
Free from the stem; close or crowded; short gills frequent; white, becoming pink, then brown; when young covered by a whitish partial veil that may develop brown stains.
Stem
4–7 cm long; 0.5–1 cm thick; more or less equal above a small bulbous base; bulb usually cuplike, featuring a scooped-out upper side; whitish, bruising yellow; with a ring that typically persists into maturity.
Flesh
White throughout; staining bright yellow in the base.
Odor and Taste
Odor phenolic or not distinctive.
Chemical Reactions
Liquid Drano yellow on cap (I was traveling and did not have KOH).
Spore Print
Brown.
Microscopic Features
Spores 5–6 x 3–3.5 µm; more or less ellipsoid; smooth; thick-walled; brown in KOH. Basidia 4-sterigmate. Cheilocystidia 15–25 x 5–8 µm; cylindric to subclavate; smooth; thin-walled; hyaline in KOH. Pileipellis a cutis; elements 2.5–5 µ wide, smooth or a little encrusted, yellow-brown in KOH.
Photo sources:
Photo 1 - Author: alan_rockefeller (Attribution-ShareAlike 4.0 International)