FUNGI INJURIOUS TO FIRS. 63 



to hymenomycetous fungi which rot the timber, such as Ayaricus hielleus, 

 Trametes radiciperda and T. Pini, Polyporus vaporarius, P. borealis, 

 P. fulvus, etc., and it is scarcely necessary to add anything to what was 

 said of these when treating of the Pines. Again, also, it happens that, 

 with the exception of Phytoplitliora omnivora, which destroys the 

 seedlings of Spruces and Silver Firs, the disease-inducing fungi all belong 

 to certain sections of the Hymenomycetes, Ascomycetes, and especially 

 the Uredineae.* 



Undoubtedly one of the most extraordinary of all these forms is 

 Calyptospora Goeppertiana, a uredinous fungus which alternates between 

 the Silver Fir (Abies pectinata), on the leaves of which it develops an 

 aeeidial form long known as ^Ecidium columnare, and the Red Whortleberry 

 (Vaccinium Vitis-idcea), a common under-shrub in the German Fir-forests, 

 the stems and leaves of which it distorts and kills by means of the 

 mycelium of its Uredo-form (known as Calyptospora or Melampsora- 

 Gwppertiana). 



Another remarkable case is that of the "Witches' brooms," very 

 common in Europe, and by no means rare in this country. I have 

 myself found these on Abies Pinsapo, as well as on A. pectinata, in 

 Windsor Great Park. " Witches' brooms " are curiously tufted masses of 

 twiggy branches which take their origin from parts of the stem attacked 

 by the mycelium of dEcidium elatinum, the Uredo-form of which is as 

 yet unknown, and possibly does not exist. The life-history was worked 

 out very thoroughly by the late Professor de Bary. f The hyphae so irritate 

 the growing tissues of the young shoots that the latter gain enormously 

 in diameter, and put forth numerous shoots which alter their whole 

 character. Thus, instead of growing outwards in a nearly horizontal 

 plane, they turn vertically upwards, and branch copiously in a fastigiate 

 manner ; then their leaves are smaller, and arranged in regular spirals 

 around the erect twigs. These leaves are infested by the mycelium, 

 and eventually bear the ^Ecidia, and fall prematurely. This mycelium is 

 perennial in the cortex, cambium, and wood of the stems, and does 

 much damage by stopping the leaders, and paving the way for rot-fungi. 

 It happens not infrequently in this country that the mycelium simply 

 sojourns in the stems, and does not lead to the full development of the 

 " Witches' broom," but only causes tumour-like swellings of the axis. 

 The treatment of infected trees resolves itself into careful pruning 

 and removal of the monstrous organs. It would be well worth the 

 time of some capable investigator to undertake further researches into 

 the nature of this disease. This malady, by the way, has nothing to 

 do with the " Witches' brooms " developed on Birches, Cherries, Horn- 

 beams and other Dicotyledons which are due to the ravages of various 

 species of Exoascus, curious ascomycetous fungi allied to the one that 

 causes "Bladder-plums." Farlow has found JEc. elatinum on Abies 

 concolor\ and A. balsamea, and it will probably turn out to be more 

 widely spread than has been hitherto suspected. 



The Silver Firs surfer from a number of other Uredineae, of which 



* The general application of these remarks to Coniferse as a whole may have to be 

 modified when Ustilago Fussii (Niessl.) on species of Juniperus has been properly in- 

 vestigated. 



t "Bot. Zeitung," 1867. 



"A Provisional Host-Index of the Fungi of 'the United States." Part III. 1891. pp. 

 158170. 



