FUNGOID PESTS OF FOREST TREES. 



389 



Pine-Leaf Cast. 

 Lophodcrmium pinastri (Chev.), PI. XXI. fig. 52. 



This little parasite has long been known on the leaves of Conifers, 

 but only recently has it been charged as a special disease, especially on 

 seedlings. Hartig says its presence is often indicated by the appearance 

 of brown blotches on the primary leaves, the rest of the leaf being purple- 

 red. The early condition of spermagonia appears first on the leaves as 

 small black spots, often killing them. 



In the final stage the conceptacles are scattered, at first innate, 

 elliptical or elongated, black, smooth, split lengthwise so that the mouth 

 opens like a pair of lips when moist, and discloses a livid-coloured disc, 

 which is composed of myriads of cylindrical asci, closely packed side by 

 side, the apices of which form the disc (115-150 x 14-16 fx). The sporidia, 

 of which eight are enclosed in an ascus, are thread-like, thickened at the 

 apex, collected in a parallel bundle (100-140x1^-2 li), the asci mixed 

 with a number of slender paraphyses which are curved at the tips. This 

 final stage only matures after the leaves have fallen to the ground. 



Known in France, Belgium, Germany, Sweden, Finland, Italy, and 

 North America. 



Hart. & Sow,. Dis. Trees, p. 110, figs. 56, 57 ; Mass. PI. Dis. 139, fig. 27 ; 

 Sacc. Syll. ii. 5819 ; Cooke, Hdbk. No. 2302 ; Grev. Sc. Crypt. Fl. t. 60. 



Conifer Rot Polypore. 



Polyporus Schweinitzii (Fries). 



This large brown polypore has the reputation of being destructive to 

 Larch, Scotch Fir, and Weymouth Pine. 



The pileus is thick, soft, and spongy, of large size (6-9 inches diam.), 

 but variable in form, rounded or angular and deformed, flattened or 

 depressed, tomentose or coarsely velvety, bright brown, supported upon a 

 thick, short stem of the same colour, which is sometimes nearly suppressed. 

 Under surface punctured with large pores, which are torn at the edge, 

 and at first greenish-sulphur colour. Spores ovoid (7-8x3^ ix). 

 Substance, when in good condition, soft and spongy, becoming harder 

 with age, and fragile when dry, of a rhubarb-brown colour. 



Known in Pine woods throughout Europe, North America, Cuba, and 

 the Himalayas. 



Hart. & Som. Dis. Trees, p. 198 ; Cooke, Hdbk. No. 739 ; Sacc. 

 Syll. vi. 4938 ; Mass. PL Dis. p. 196. 



Another woody fungus called Trametes pini has a like reputation, 

 but it is too rare in this country to require notice. 



On the light sandy soil of France and Germany, the roots of Conifers 

 are attacked and killed by the mycelium of Bhizina undulata (Fries). 

 Hart, d Som. Dis. Trees, p. 124, figs. 61 to 69. 



