THE FUNGI WHICH CAUSE PLANT DISEASE 161 



Spores 4 to many-celled, spindle-form 



Spores 4-celled, mostly hyaline. ... 6. Gloniella. 



Spores 4 to many-celled, brown 7. Rhytidhysterium. 



Spores muriform, hyaline 8. Hysteropsis, p. 161. 



Spores filiform, 1-celled 9. Lophodermium, p. 161. 



Of these genera only four are important here. 



Hypodermella Tubeuf (p. 160) 



This differs from the next genus in its pyriform unicellular 

 spores; asci 4-spored. Two species, both European and economic. 

 H. larius Tub. affects larch needles in Europe. ®^ 

 H. stilcigena Link is on pine needles. 



Hypoderma De CandoUe (p. 160) 



Apothecia oblong, opening through a thin black cover by a 

 long fissure; asci 8-spored; spores cylindrical or fusiform, 2-celled 

 at maturity; paraphyses hooked at the end. 



H. desmazieri Duby,^* on pine needles in America and Eu- 

 rope. 



Amphigenous; asci broadly clavate, sessile; spores hyaline, 

 linear-elliptic, obtuse and 2-rowed. 



H. laricis, H. strobicola, H. pinicola, produce premature leaf 

 fall in various conifers. 



Hysteropsis Rehm 



Asci clavate, 8-spored; spores hyaline, muriform; paraphyses 

 branched, forming an epithecium. 

 H. brasiliensis occurs on cacao trees. 



Lophodermium Chevall 



Spores long, thread-like, continuous; conidiospores in pycnidia. 



L. pinastri (Schr.) Chev. occurs in Europe" and America on 

 Pinus sylvestris especially on young plants causing the leaves to 

 fall. The first year pycnidia only are formed, the asci not ap- 

 pearing until the second year.^ 



