6oo 



Poisonous Fungi. [nov., 



POISONOUS FUNGI.* 



I. — Amanita phalloides, Fr. 



Of those British fungi which are known to be poisonous, 

 one of the most dangerous is the subject of the present plate, 

 Amanita phalloides. Both in Britain and on the Continent 

 many cases of fungus poisoning have been caused by this species, 

 and in not a few instances the results have proved fatal. In 

 the United States also it is regarded as one of the most poisonous 

 of all fungi. 



The genus Amanita belongs to that section of the Agrari- 

 caceae, or gill-bearing fungi, in which the gills do not turn 

 pink or purple, as in the true mushroom, but remain per- 

 sistently white. It is distinguished from other genera of the 

 section by the possession of both a basal volva and a ring 

 on the stem. The volva is a cup-like structure attached to the 

 base of the stem. 



There are several species of Amanita found in Britain, and 

 the one here figured is frequently met with during the autumn. 

 In this species the cap (pileus) is viscid or slimy when moist, 

 of a pale yellow or greenish colour, and 3 to 4 ins. across. The 

 stem is white and smooth, solid at first, but becoming hollow 

 with age ; the base is bulbous, and the volva is usually well 

 developed. The ring clothing the upper part of the stem is 

 large and pendent. In the very early or " button " stage 

 the whole of the pileus is enclosed within the volva ; as the 

 plant expands the volva is ruptured and the pileus bursts 

 through, leaving the ragged edges of the volva attached to the 

 base of the stem. Considerable variation is found in the way 

 in which the volva is ruptured, and it frequently happens 

 that portions of this structure remain on the top of the pileus. 

 In this way the pileus becomes studded with irregular scales 

 or warts. 



Amanita -phalloides usually occurs in woods, and on this 

 account it is not likely to be confounded with the common 

 mushroom. The colour of the pileus varies according to the 

 amount of shade in the woods, being greenish or almost olive 



* An article on an edible fungus — the Common Morel, Morchella esculenta, appeared 

 in this Journal, September, 1908, p. 431. 



