492 THE FUNGI WHICH CAUSE PLANT DISEASE 



P. apiicola Speg. is recorded on celery.'^ 



P. brassicse Thiim. on cabbage is probably identical with 

 P. oleraceae. 

 P. roumii Fr'on. is said to cause a serious cotton disease in 



Africa.*' 



P. batatSB E. & H.*^ 



Pycnidia blackish, gregarious, immersed; conidia terete, ovoid; 

 conidiophores slender. The cause of dry rot of sweet pota- 

 toes. 



P. chrysanthemi Vogl. is found on leaves of chrysanthemum 

 causing them to wilt. 



P. malvacearum West is noted on European hollyhocks; 



P. devastatriz Berk, on cultivated lobeUas; 



/tof 



Fig. 337. — P. oleracea. A, showing pycnidia with spores stream- 

 ing out; B, section; C, spores. After Manns. 



P. dahlise Berk, on stems and flowers of Dahlia. 



P. cyclamense Hals, is given as the cause of Cyclamen leaf spots 

 but without ample description. 



P. oleandrina Del. is on the rose, laurel, etc. 



P. pithya Sacc. seems to be parasitic on the fir causing con- 

 striction and death of twigs. 



P. strobi (B. & Br.) Sacc. is prevalent on white pine in Europe. 



P. strobilinum P. & C. is closely related to the above. 



P. sordida Dur. & M. occurs on Carpinus. 



P. ribesia Sacc. Pycnidia collected, erumpent, spores oblong- 

 fusoid, 10 X 3^ ju, hyaline. In branches of Grossularise. 



Several undetermined species have been reported, among them 



