146 



THE FUNGI WHICH CAUSE PLANT DISEASE 



orange-red with a pale margin; asci 109 x 8-9.5 fi; spores 19-20 x 

 6.5-8.5 |i, hyaline. 



Hymenoscypha Fries (p. 136) 

 This genus of over two hundred species is mainly saprophjrtic, 

 one species only in its conidial stage being parasitic. 



Ascoma sessile or short-stipitate, usually 

 smooth; asci cylindric to globoid, 8-spored; 

 spores elliptic, blunt to pointed, hyaline; 

 paraphyses filamentose, apically enlarged, 

 hyaline. 



H. tumulenta P. & D." in its conidial 

 stage as Endoconidium, affects rye grain 

 causing it to shrivel and assume poisonous 

 properties. The conidia are borne en- 

 dogenously in the terminal branches of the 

 hyphse and escape through an opening in 

 the end of the branch. 



Fig. 103. — ^Hymenoscy- 

 pha. J, habit sketch; 

 K, ascus and paraphy- 

 ses. After Rehm. 



Mollisiaceae (p. 134) 



Ascocarp free from the first or simken in 

 the substratum and later erumpent, at first 

 more or less globose, becoming flattened; asci 8-spored, opening 

 by a slit; spores hyaline, 1 to many-celled; paraphyses slender. 

 Above four hundred species. 



Key to Genera of Mollisiacese 



Ascocarp fleshy, waxy, rarely membranous. I. Mollisiese. 

 Ascocarps not sunken in the substratum 

 Ascocarps on a visible, often radiate 

 mycelimn 

 Spores elongate, often fusiform, 



1-celled 1. Tapesia. 



Spores filiform, many-celled 2. Tiichobelonium. 



Ascocarps not seated on a visible my- 

 celium 

 Spores 1-celled 



Spores spherical 3. Mollisiella. 



Spores elongate 4. Mollisia. 



