[ THE WALNUT 



teristic hairy formations. None of these insects has as 

 yet been noticed on the walnut in these Islands. 



Two minute fungi, viz: Phomopsis juglandina (Fuck) 

 Sacc. and Macrophoma juglandaria Sace., are frequently 

 found on the dead twigs of the walnut at San Antonio. 

 Boschetto and Gneina, but probably are only saprophytic. 

 However, many species of fungi are known to attack the 

 walnut in Continental Europe. Thus Cvyptosporium 

 nigrum Bon., produces round or irregular brown spots 

 on the leaves, and Gnomonia leptostyla Ces & De Not., 

 causes the formation of irregular greyish brown blotches 

 with dark dots on the under surface of the leaf 

 Phyllosticla juglandina Sacc. and Ph. fuglandis Sacc. 

 produce large irregular blotches on the foliage, sur- 

 rounded *by a dark margin, Microstroma jugiandis Sacc. 

 produces blotches of a light green colour on the tender 

 foliage, with a network of white mould on the under 

 surface; and Marstonia jugiandis Sacc. causes roundish 

 blotches of a rusty grey colour, with small brown dots, 

 on the under surface of the leaf. Phyllactinia suffufta 

 Sacc. causes the well known male bianco of the walnut, 

 covering both surfaces of the leaf with a white mould, 

 upon which later on, minute black dots make their 

 appearance. Exoascus jugiandis Berk., a blister fungus, 

 is found also on the leaves of the walnut in Italy. Various 

 species of Polyporus, such as P. sulphur eus Fr., P. squa- 

 mosus Fr., P. cinnabarinus Fr., P . foment arius Fr., P. 

 ignarius Fr., as well as Daedalea cinnabarina Seer., are 

 found on the stems and thick branches of the walnut all 

 over Europe, but none of them has been noted on the 

 walnut of these Islands. Armillaria mellea Val. is a 

 frequent cause of root-rot in Italy, and has been noted 

 once or twice on walnut trees at Boschetto. 



The fruit or nut of the American walnut or Black 

 walnut (fuglans nigra L. North America) is sometimes 

 eaten like that of the common walnut, but this tree is 

 chiefly grown for its valuable timber, and as an ornamen- 



