578 THE FUNGI WHICH CAUSE PLANT DISEASE 



The form is an atypical one in 

 that it produces two kinds of 

 spores; one kind which is usually 

 septate 



Heald ^ also Stewart and Hodg- 

 kiss^"* have described it as the 

 cause of bud rot of carnations, while 

 the latter authors also mention it 

 in connection with a disease known 

 as "silver top" of June grass in 

 Fig. 387.— s. poae. ii.Hyphabeai^ which the panicles wither' as they 



ing conidiophores and macrooo- i ,i .i_ 



nidia. 13, Hypha bearing co- expand, thougli the authors express 

 &HeSd. '^^ "^«"<»"idi^ doubt as to its actual causal relation 



to the disease. A mite appears to 

 be the carrier of the spores. Cultural studies and cross-inoculation 

 showed the fungus form on the two hosts to be identical. 



Botrytis (MicheU) Link (p. 576) 



Hyphse creeping; conidiophores simple or more or less markedly 

 dendritic branched, erect, branches various, thin and apically 

 pointed, thick and obtuse or cristate; conidia variously grouped 

 at the apex of the branches, never in true heads, continuous, 

 globose, elliptic or oblong, hyaline or light colored. 



In part =Sclerotinia. See p. 136. 



A genus of some two hundred or more species, several of them 

 of great economic importance. 



This form-genus contains many parasites on various hosts. 

 In some instances they are known to include ascigerous stages, 

 (Sclerotinia), in their life cycle; in others no such relation is known, 

 though it has often been assumed on quite untenable grounds. 

 Specific limitations are but poorly imderstood and the relations 

 between the various forms and between these forms and the as- 

 cigerous stages are in a state of much confusion c. f. (p. 137). In 

 some instances the same conidial stage is claimed by different in- 

 vestigators as belonging to two distinct ascigerous species, a 

 manifest impossibility, (e. g., S. fuckeliana and S. libertiana with 

 B. cinerea.) 



