222 DISEASES OF CULTIVATED PLANTS 



HERPOTRICHA (FCKL.) 



Perithecia carbonaceous, globose, clothed with long, crisped, 

 creeping hairs, apex almost glabrous ; asci 8-spored ; spores 

 hyaline, many septate ; paraphyses present. 



Pine leaf fungus (Herpotricha nigra, Hartig) is very 

 destructive to young larches in elevated regions; it also 

 attacks Abies excelsa, Juniperus communis, and/", nanus. The 

 brown mycelium envelops branches and even whole trees in 

 a dense weft. The lower branches are often anchored to the 

 ground by the mycelium. After the leaves are killed they do 

 not fall, but remain fixed to the branch by mycelium. The 

 dead leaves also become covered with a weft that bears the 

 perithecia. 



Perithecia subglobose, black, with long deflexed hairs near 

 the base ; spores i- soon 3-septate, constricted at the middle. 



The fungus is met with in upland regions more especially, 

 and grows vigorously under the snow. Nurseries should not 

 be formed at high elevations, nor in valleys where the snow 

 lies for a long time. 



Hartig, Alleg. Forst u.Jagd. Zeit., 1888. 



Prillieux, Malad. des Plantes Agric., 2, p. 212 (1897). 



CLAVICEPS (TuL.) 



Stroma stipitate, capitate, springing from a sclerotium ; 

 perithecia immersed in the capitate stroma ; asci 8-spored ; 

 spores needle-shaped, septate. Spormogonia and conidia 

 present in some species starts the disease anew. 



Apart from the loss occasioned by the fungus, its action on 

 animal life is very serious. Rye bread, containing much 

 ergot, is the cause of a terrible malady characterised by 

 gangrene of the extremities. Abortion is also caused by 

 partaking of sclerotia along with food. A serious epidemic of 

 cattle in the United States, at first supposed to be the dreaded 

 ' foot-and-mouth disease,' was proved to be caused by ergotised 

 food. 



The most certain method of checking the disease is to 

 collect the sclerotia, which can be sold for medicinal purposes. 

 In the case of grass, cutting before the sclerotia are ripe also 

 arrests the disease. 



Tulasne, Ann. Set. Nat., Ser. 3, 20, p. 5. 



