THE HYMENOMYCETES 



267 





of Fig. 237) and in a ring attached to the stalk below the gills 

 (Fig. 237, r), while in certain types (Amanita, etc.) there is a 

 large cup (volva) at the base of the 

 plant out of which the stalk rises. 



It is rather general popular usage 

 to apply the term mushroom to all 

 toadstools and other fleshy fungi 

 which are edible. There are no gen- 

 eral rules for distinguishing the edible 

 from the non-edible fungi which do 

 not have exceptions; but the collector 

 may readily learn the characters of 

 the most poisonous species, and like- 

 wise become acquainted with a num- 

 ber of choice forms which are easily 

 recognized. 1 It is a good principle, 

 however, to rest satisfied with, a 

 knowledge of a few absolutely safe 

 mushrooms and not to experiment 

 with those that are not fully known. 

 The most poisonous species of the gill FIG 23g Gillg of mushroom 

 fungi are in the genus Amanita and (Coprinus comatus) 



have generally large cups, rings, and Across section of gills showing 

 white spores, and may be readily 

 recognized when carefully examined. 

 However, the very poisonous Amanita 

 muscaria, "fly agaric," has no cup. The 

 commonest mushroom of the market 

 (Agaricus campestris) is a form extensively cultivated, but 

 which also grows in the fields. These mushrooms are raised 

 in cellars and caves, in specially prepared, heavily manured 

 beds, which are planted with masses of mycelium called 



1 See Farlow, " Some Edible and Poisonous Fungi," United States Depart- 

 ment of Agriculture, Division of Vegetable Physiology and Pathology, Bul- 

 letin 15, 1898. 



fruiting surface (hymenium) ; 

 B, portion of fruiting surface 

 illustrating three basidiawith 

 spores and two from which 

 the spores have fallen off, 

 showing the spore-bearing 

 stalks (sterigmata) a 



