REPORT OF THE BOTAMST 



263 



SESSIONAL PAPER No. 16 



MUSHROOMS AND TOADSTOOLS. 



Considerable interest is shown by some correspondents in the use of mushrooms 

 and toadstools for culinary purposes. These terms are commonly used to describe 

 some of the larger fungi and usually in such a way as to include the edible forma 

 under the title of mushrooms and to designate such as are poisonous or inedible as 

 toadstools. There is, however, no general rule to distinguish a poisonous specimen 

 from an edible one in spite of the many more or less fantastic opinions that have 

 been expressed on this point. It is, for instance, commonly believed that all mush- 

 rooms which turn to a bluish colour when cut and exposed to the air are poisonous, 

 whereas this effect is simply due to the oxidation of the fatty matter contained in 

 these particular forms. Likewise no importance can be attached to such indications 

 as the turning black of a silver spoon when clipped in the cooked mushrooms, which is 

 supposed to denote poisonous properties. 



The common Held mushroom (Agaricus campestris) and its cultivated forms are 

 among the most palatable of fungi, though some closely-related ones are highly 

 poisonous. The poisonous principles of fungi can only be established by a careful 

 and difficult chemical analysis, but the collective experience of many individuals in 

 testing the edibility of different kinds by the actual eating of them, has shown the 

 larger number to be harmless and of delicious taste. In consequence of what has just 

 been said, it will be seen that a careful study of the mushrooms is necessary to recog- 

 nize any particular specimen as useful for food or the reverse. This study needs a little 

 closer attention on account of the risks involved but otherwise does not differ from 

 the methods of acquiring a knowledge of other wild plants. Certain common mush- 

 rooms, moreover, are so distinctive in form and appearance that they are easily recog- 

 nized and a mistake is not possible. 



the common mushroom {Agaric us campestris, L.). 



The common field mushroom occurs in fair numbers in fields, gardens and open 

 woods. It varies much in size according to the place of growth and time of year. 

 The diameter of the cap may be from one to four inches or more, while the stipe or 

 stem may attain a length of from one to four inches, and a thickness of a quarter to 

 one inch. The cap is hemispherical when young, becoming fairly well expanded with 

 age. Viewed from above, the whole fungus usually appears white, but may be seme- 

 times slightly tinted with red or brown. When turned over, the lower surface of the 

 cap will be seen to be covered with radiating knife-like folds — the gills — which in the 

 early stages may be pale rose but later turn dark-brown, purplish-brown or even black. 

 In this mushroom the gills are never attached to the stipe. The stipe is white and 

 -olid, and gradually enlarges towards the base. It generally carries a ' ring ' of mem- 

 branous tissue, formed of the remains of a membrane covering the fungus in its 

 earliest stage (the so-called 'buttons')' which is tern as the fungus grows and the 



