SEPTORIA. 



477 



cultivated parsley in Europe and Britain, 

 enemy of celery in the United States. 



S. armoraciae Sacc. On 

 horse-radish in America. 



S. consimilis Ell. et Mart, 

 frequents lettuce in America. 



S. lycopersici Speg. This 

 parasite, originally observed in 

 America, has recently been de- 

 scribed by Briosi and Cavara on 

 tomatoes in Italy. It causes 

 spots on leaves, stems, and 

 fruits, inflicting thereby con- 

 siderable loss on cultivators. 



The following are im- 

 portant forms on other 

 cultivated plants : 



S. graminum Desm. 

 causes light spots on leaves 

 of vyheat, oats, and grasses. 

 It has been observed to 

 injure the cereal crop in 

 Italy.-' It is recorded for 

 Britain and U.S. America. 



S. cannabis (Lasch.). 

 This on leaves of hemp pro- 

 duces spots, vfhich are at 

 first whitish, then yellowish 

 with dark margins. The 

 pycnidia are embedded in 

 the upper side of the leaf. 



The following species 

 have caused injury to 

 garden plants : 



S. dianthi Desm. Car- 

 nation-spot." The disease 

 appears on the leaves and 

 stems as rounded spots of 



A variety {apii Br. et Cav.) is an 



Fig. 297. — a, Leader-shoot of Spruce, partially 

 killed and defoliated, h, Pycnidia emerging from 

 the rind and the leaf -sears ( x 5). c, Formation 

 of conidia inside a pycnidium ( x 240). d, Spores 

 germinating in water, e, Spores germinating in 

 nutritive gelatine. (After K. Hartig.) 



' Cavara (ZeiiscA. /. Pflanzenlcrankheiien, in., p. 23) regards this and S. tritici 

 with its varieties, as forms of a single species ; also Eriksson (Om Nagra 

 sjukdomar a odlade Vaxter, 1890). 



* Atkinson, " Carnation Diseases," at American Carnation Society, 1893. 



