124 The Scottish Naturalist. 



ON SOME LEAF-PARASITES NEW OR RARE IN BRITAIN. 



By JAMES W. H. TRAIL. 



IN the course of the past summer I have met with two or three 

 fungi, living in the interior of the tissues of the host-plant 

 (for the most part in the leaves), of which I cannot find notices in 

 our British lists. They have all been found in the vicinity of 

 Aberdeen, and will doubtless be found to occur elsewhere if 

 looked for. 



Doassansia Alismatis, Cornu, was rather plentiful in the 

 leaves of A lis ma Plantago, in a small pool near Aberdeen at Cults. 

 The fungus was described this summer in the " Annates des 

 Sciences Naturelles" (vi. Ser., t. xv., 1883, 285, pi. 16, figs. 

 1-4). The genus is characterised as follows by its author (I.e.) : — 

 " In planta viva parasitica ; spora coacervatce,mcarceratce. Cortex 

 sort cellulis simplicibus, arete adnatis. Gerniinatto sporarum, ut i?i 

 Entylomatibus, coronam sporidioriun effingit." The species under 

 review is characterised thus : — D. Alismatis, effnsa, circiuans, in 

 utraque pagina Alismatis Pla?itaginis. Junto mense in locis uligi- 

 nosis." Sori .2-. 2 8 mm. diam., and .16-. 2 mm. deep ; spores 

 .01 8-. 01 2 nun. diam. The above description applies in all essen- 

 tial particulars to the specimens formed by myself; but some addi- 

 tional points may be noted here. The leaves for a time do not 

 show much sign of injury ; but here and there roundish spots, 

 about 10-15 mm - across, begin to turn a yellowish-green. After 

 a time the leaf assumes a fading aspect, its colour becoming- a 

 yellowish-green, verging towards brown, and in the spots occupied 

 by the fungus a number of small dark dots may be seen, resem- 

 bling the spore-clusters of a Puccinia. These are the spore-masses, 

 enclosed in an envelope found of a layer of oblong or wedge- 

 shaped cells, arranged side by side, with the narrow ends inwards. 

 There are usually many of these masses in each spot. On making 

 a transverse section of the leaf, the masses are seen to be usually 

 rather flattened, the dimensions being from .16 mm. to '24 mm. 

 in breadth, by about one-fourth less in depth. The spores are 

 very numerous in each mass. They are nearly spherical, aboat 

 .008 mm. in diameter (instead of from .012 mm. to .018 mm., 

 as in France), pale brown, and thin-walled. The cells of the 

 outer wall are brown in colour, and are about .02 mm. long, by 

 .008-.01 mm. broad. 



Entyloma Calendulse, Oudemans, is common in leaves 

 of Hieracimu vulgatum near Aberdeen, alike in shady spots in 

 woods and on the bare sandhills along the coast ; but I have not 

 met with it before autumn. Its presence is easily detected, inas- 

 much as it causes in the leaves roundish spots about 5-6 mm. 

 across. These spots are not thickened at all, but they become 

 pale yellowish or whitish-green, changing after a time to brown as 



