Order Hymenomycetes Tribe Pileati  

Agaricus campestris Linn.  

Name—campus, a plain, a field  

Series Pratellae Subgenus Psalliota 

Species Characters. A. campestris. Pileus at first globose, then more or less campanulate, deplanate when fully expanded, thick, fleshy, sometimes smooth sometimes scaly, white, tawny, fuliginous or brown; epidermis peels easily; lamellae unequal, free or connected with the stalk, broad, at first flesh color deepening in age to light or dark brown; veil forms a partial ring-like investment more or less persistent; stalk short, stout, subequal, distinct from the pileus. There are several varieties of A. campestris common to all are a fleshy pileus & the mycelium will when under cultivation produce the A. arvensis. There is a marked difference between the wild & the cultivated A. campestris. Those which we gather from our meadows are filled with a delicious aroma, both to the smell & the taste and they form an extremely delicate & digestible diet. Those that are cultivated are neither so delicate or so healthy. Perhaps it might require an acute & cultivated taste to detect the difference but when once known it is very marked. According to Vittadini those which have a white smooth & continuous epidermis are the most sapid of any. Spores 0.00032 × 0.002 inch.