182 HARDY CONIFEROUS TREES. 



their wide range or injurious effects, will be brought under 

 notice. 



The common juniper {Jtmiperiis communis) and the Savin 

 (/. Sabind), the former in particular, suffer severely from the 

 attacks of a species of well-known fungus, Gymnosporangia. 

 This fungus produces the peculiar woody, knob-like swellings 

 which so distort and kill out numbers of specimens of the 

 juniper on our English commons and downs. It spreads 

 with great rapidity, and would seem to have been on the 

 increase of late years, as in the Midland and Southern English 

 counties, large extents of juniper have been almost totally 

 destroyed by its ravages during the past twelve months. 

 When badly attacked with the fungus, the plants wear a 

 rusty, meagre appearance, and gradually die off with the 

 increase of the disease. I have counted as many as seven 

 of these woody swellings on a branch only 4 feet in 

 length, and on a single bush hardly exceeding 8 feet in 

 spread I counted thirty-seven. To the Irish juniper (/. 

 communis hibernicd) the disease likewise extends. By cutting 

 off the affected shoots, and dressing those on the main stems 

 with fir tree oil, much good has been brought about. 



Several species of Pinus, particularly P. Pinaster^ P. 

 Strobus, P. excelsUy P. silvestriSy and P. montana^ are attacked 

 by Trametes radiciperda, the mycelium of which causes 

 the roots and other attacked portions to rapidly decay. 

 In replanting ground from which diseased trees have been 

 removed, the greatest care should be exercised that every 

 portion of the old stump and roots are taken from the ground, 

 the mycelium travelling very rapidly from root to root. The 

 Alaska cypress {Cupressus nootkatensis) has been killed out- 

 right by the mycelium of Trametes, the disease not only 

 affecting the roots, but the stem and branches. In one par-, 

 ticular case the cause was distinctly traced to a piece of 

 plank that by mistake had been left in the soil, and with which 

 one of the larger roots of the cypress had come in contact. 

 The plank was completely enveloped in the mycelium of the 

 fungus. When attacked, the cypress was a healthy vigorous 



