142 FUNGOID PESTS OF CULTIVATED PLANTS. 



again. Diseased roots, if not too far infected, should be cleaned and 

 pruned before replanting, and well washed with some fungicide, when, in 

 some cases, they may possibly recover ; otherwise they should be burnt 

 forthwith. 



Journ. B.H.S. xxix. 1904, p. xliv. 



ORCHARD AGARICS. 

 Armillaria mellea (Vahl). 



This very common Agaric grows in large clusters at the base of stumps 

 and old trees, and often in orchards where the mycelium extends to and 

 becomes parasitic on growing trees, causing great mischief. 



The fungus grows in dense clusters with a pale honey-coloured pileus 

 or cap, two to three inches across and a paler stem four to six inches long, 

 with a distinct collar or ring surrounding the stem above the mid die and a 

 profusion of white spores, which fall and settle on surrounding objects as a 

 dense white powder. (Fig. 19.) 



The black strands of mycelium, thick as fine twine, and known as 

 " rhizomorphs," are well known, and generally belong to this Agaric. 



Sacc. Syll. vi. 289; Mass. PL Dis. p. 202, fig. 47; Cooke Hdbk. 

 No. 36, fig. 36 ; Cooke Illus. pi. 32. 



PHOLIOTA SQUARROSA (Mull.). 



Dense tufts of this Agaric may often be seen at the base of trunks in 

 orchards, and is capable of doing great injury by the mycelium becoming 

 parasitic. The Agaric is similar in size and form to the above Armillaria, 

 but both cap and stem are yellowish brown, densely clad with projecting 

 brown scales, and the spores, and consequently the gills, are brown. The 

 smell is strong. 



Sacc. Syll vi. 3093 ; Mass. PL Dis. p. 208 ; Cooke Hdbk. No. 297 ; 

 Cooke Illus. pi. 367 ; Sow. Fung. t. 284. 



TINDER POLYPORE. 



Fomes fomentarius (Fries). 



It is strongly contended by some writers that the woody Polypores 

 which are common mostly on forest trees will attack fruit trees as 

 wound parasites, and compass their destruction. * One species is found 

 sometimes on fruit trees, which become as hard as a wooden log. In 

 shape it somewhat resembles a horse's hoof, with a smooth upper surface 

 of a dark brown colour attached firmly by the back, so as to project like 

 a bracket. The under surface is almost flat, or a little concave, pale, and 

 punctured with minute pin-holes or pores close together all over the 

 surface. These pores contain the spores, which are snuff-coloured and 

 profuse, so that they fall when mature on all surrounding objects like snuff. 

 This is a wound parasite, the spores finding an entrance into its victim 

 tree through a wound y and afterwards developing on the surface. 



One of these wound parasites is Fomes fomentarius, which is common 



