496 THE FUNGT WHICH CAUSE PLANT DISEASE 



Asteroma De Candolle (p. 482) 



Pycnidia very small, globose, erumpent, often on a mass of 

 hyphae; conidia ovate or short cylindric. In part =Gnomonia. See 

 p' 274. 



About forty species chiefly parasitic. 



A. padi (D. C.) Grev. on Prunus=Gnomonia padicola. See 

 p. 275. 



A. geographicum (D. C.) Desm. occurs on various species of 

 Pomaceae; 



A. punctiforme Berk, on the rose; 



A. stuhlmanni Hen. on bananas and pineapples in Africa. 



A. codisei All. is said to be a serious parasite of Codiseum.^^ 



Vermicularia Fries (p. 482) 



Pycnidia superficial, or erumpent, globose depressed, to globose 

 clavate, leathery or carbonous, black, ostiolate or not, beset 

 with rather long, stiff, septate, dark colored bristles; conidia 



cylindric-fusoid, often curved. 



Some one hundred thirty 

 species, chiefly saprophjrtes. 

 V. dematium (Pers.) Fr. 

 Pycnidia erumpent, superficial, 

 80-120 /!> conic, then depressed, 

 often confluent, black, spines 

 pale at the ends, 150-200 x 5 m; 

 conidia cylindric-elongate, 20 x 

 HSV** 4-^ M, apically rounded, curved. 



Fio. 341.— V. dematium. c, a nearly Commonly a saprophyte, this 

 rhypiue.'""Ai^'R^k ^' '^°""' ^™S^ Occasionally causes as- 

 paragus disease.*^ In Europe it 

 is reported as the cause of much loss to the ginseng crop. On 

 this plant it produces a stem anthracnose. The fungus was 

 isolated and its cultural characters studied by Reed.** 

 V. trichella Fr. 



Pycnidia ovate, small, black, spines long, at the apex of the 

 pycnidium; conidia fusoid, curved, pointed, 16-25 x 4-5 /x. 



