184 



The Plant World. 



same time the fact that no such insect was found on the roots 

 of the dandeUons in question is not sufficient to ascribe frond- 

 escence of the bracts to possible mechanical injurv, since in 

 all probability this would have brought about fasciation. 

 Phtzka * observed numerous instances of virescence in dif- 



Fig 2 Fasciation of J?M(//)t'cA! a /i!r/a X 4,'l^ 



ferent Compositae and ascribed them to the eft'ect of a fungus, 

 Puccinia compositarum. He also noted that the abnormality 

 was limited to those plants which grew on a soil rich in Ume. 

 Molliard f ascribes virescence of Trifolium re pens to Polyn- 

 thrincium Trifolii Kunze, while Phytoptus seems to have been 



*Plit7.ka, A , Beitrag zur Teratologic der Komposileii. Ocster. Hot. /.riischr. 52' 

 100, 159. 1902. 



t.MolHard, M., Cas de virescence et de fasciation d'origine parasitairc. Rev. gcu. dc 

 Bot. 12: 325. 1900. 



