The Biology of Armillaria mucida, Schrader. 
BY 
C. E. C. FISCHER, 
Indian Forest Sewice . 
With Plates XXXVII and XXXVIII. 
A RMILLARIA MUCIDA is a widely distributed gill-fungus wherever 
jlX. the beech occurs. Saccardo (23) gives its habitat as ‘ . . . totius 
Europae et Americanae federatae, frequens,’ and according to Mcllvaine 
(16) its distribution in America extends to the States of North Carolina, 
Pennsylvania, and West Virginia. 
There appears to be no special literature on the subject of this plant, 
and a perusal of the references to it in textbooks and floras leaves some 
doubt in the mind as to whether it should be described as a parasite of the 
beech or as a saprophyte on dead beech wood. Generally speaking, we 
may take it that the older works treat it as a saprophyte and more recent 
ones as a parasite, as will be seen from a perusal of the following extracts. 
Schrader, 1794(24), says: 4 Hab. ad Fagos emortuas ’ ; Fries, 1821 
(10): ‘In truncis vetustis, apprime Fagi ’ ; Patouillard in 1886 (19) gave: 
* . . . sur les troncs pourris 5 ; Lambotte (13) has : ‘ . parmi le gazon, sur les 
racines ou sur les troncs coupes du hetre.’ 
On the other hand, we have Massee’s account (15) of a successful 
infection : ‘ At High Beech, Epping Forest, ... a healthy branch of a beech 
having been broken off, the wound was inoculated with the spores of 
A. mucida. At the end of the second season after the inoculation the 
branch was killed for a considerable distance, and the sporophores of the 
fungus appeared in abundance. The spores also germinate readily on very 
small wounds made in the bark.’ 
It is obvious that sufficient information has not been given, and in the 
absence of statement to the contrary we are justified in believing that no 
precautions were taken to exclude infection by other fungi. Some parasitic 
Aingus, e.g. Polyporus fomentaruts^mdiy have gained entry and prepared the 
way for A. mucida by killing the tissues. 
Cooke (6), in 1906, wrote of this same fungus : ‘ ... so commonly seen 
on beech trees . . . has been charged with being a wound parasite, capable 
[Annals of Botany, Vol. XXIII. No. XCII. October, 1909.] 
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