FUNGOID PESTS 



Pine Cluster-cups (Peridermium Pint). The cluster-cups, which appear in 

 May or June, usually on the Scots Pine, and sometimes on the Weymouth 

 Pine, are of two forms, those found on the leaves being cylindrical or 

 laterally compressed, and having an irregularly torn margin ; others, found 

 growing in crevices of the bark on the young twigs, are larger and inflated, 

 and have the mouth spreading and much torn. The powdery a?cidiospores 

 are orange coloured. The mycelium is perennial in the bark, bast, and wood. 

 The cells attacked by the haustoria or minute suckers of the mycelium 

 lose their contents, and afterwards secrete turpentine in considerable quantity, 

 which escapes through cracks in the bark. When the disease encroaches on 

 the wood, and checks the flow of sap, the branches die. The uredo and 

 teleutospore stages are thought by some authorities to be the Senecio Rust, 

 (Coleosporium Senecionis), and this name is sometimes applied to the cluster-cups. 



Black Poplar Rust (Melamspora populina) occurs on the leaves of the 

 Black, Balsam, and Lombardy Poplars. The brown pustules of the uredo 

 are roundish, and contain orange-yellow spores, mixed with capitate para- 

 physes. The flat pustules of the teleutospores are generally crowded and 

 often confluent, reddish-brown at first, and afterwards forming blackened 

 crusts. The cylindrical pale brown teleutospores are closely packed side by 

 side, becoming angular by compression. 



Sulphury AVood-rot (Polyporus mlfereus) is a large and showy poisonous 



fungus found as a parasite on the trunk of various trees, such as Oak, Alder, 



Willow, Poplar, Pear, Apple, and Larch. In the young state it is a round 



fleshy knob, but soon grows into an irregularly flattened body, crisped and 



waved on the margin, often with several overlapping portions or pilei, one 



above the other. A well-grown specimen may measure a foot in expanse, 



and weigh several pounds. The fungus is a bright sulphur-yellow, becoming 



paler on the smooth upper surface when old. It is brittle, with a soft 



whitish flesh and a disagreeable smell. Beside the usual reproduction by 



basidiospores, there are also conidia produced in abundance from the mycelium 



growing in cavities of the wood, or sometimes in the flesh of the polypore. 



The fungus is an annual, growing rapidly, and decaying in the autumn. 



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