212 FUNGOID PESTS OF CULTIVATED PLANTS. 



It is suggested that young trees thus infected should be felled to save 

 the rest. 



Sacc. Syll. i. 2426 ; Mass. PL Dis. p. 112 ; Hart. & Som. Dis. 

 Trees, p. 99, figs. 46-49 ; Cooke, HdbJc. No. 2502. 



BEECH-LEAF ANTHRACNOSE. 

 Glceosporium Fagi (Desm.). 



This occurs on the under surface of Beech leaves, forming rather 

 rounded tawny spots on the upper, and greenish on the under surface. 

 The pustules are minute and honey-coloured, seated upon the spots. The 

 conidia are oblong or sometimes rhomboidal (15-20x 7-8 p), with two or 

 three small guttules, produced at first at the apex of pedicels collected in 

 bundles, within the pustules, and expelled when mature in tendrils. 



Known also in France, Belgium, Austria, and Italy. 



Sacc. Syll. iii. 3728 ; Grevillea, xiv. p. 124, No. 620. 



The leaves are liable to show brown blotches caused by SpJicerella- 

 Fagi. 



BEECH SEEDLING ROT-MOULD. 

 Phytophthora omnivora (De Bary), PI. XX. fig. 21. 



This rot-mould has a habit of attacking almost indiscriminately a large 

 number of plants, among which are included the seedlings of Beech. 

 Gaps are often made in seed-beds by this pest, which spreads rapidly 

 when once it gets a footing. At first dark-coloured blotches appear on 

 the cotyledonary leaves, with dark lines on the stem. The mycelium is 

 furnished with minute roundish suckers, which pierce the cells to obtain 

 nutriment. The threads are variously branched, but sparingly, and on 

 one side, sometimes inflated in nodules at intervals, below the apex. 

 Conidia ellipsoid or lemon-shaped (50-60 x 35-40 /z), with a prominent 

 papilla at the apex, when mature liberating as many as fifty zoospores. 

 Resting-spore globose, smooth, yellowish-brown (24-30 ^ diam.), often 

 clustered together. 



Known also in Germany. 



Diseased plants should be at once removed from the seed-beds. 

 Oospores will retain vitality for four years ; hence the soil which has 

 produced diseased plants should not be used again. 



Sacc. Syll. vii. 803 ; Mass. PL Dis. p. 66, fig. 8 ; Hartig & Som. 

 Dis. Trees, p. 58, figs. 14-16; Marshall Ward, Timbers, &c. p. 271, 

 figs. 42-44. 



BEECH AGARIC. 

 Armillaria mucida (Schr.). 



The slimy-white, or greyish -white, Agaric seen so commonly on dead 

 Beech trees has been charged with being a wound parasite, capable of 

 attacking a healthy branch, when broken or wounded, and causing death 

 and decay. 



The cap is from one to four inches across, hemispherical, then 

 flattened, whitish or greyish-white, very glutinous, often growing in 



