DISCOID FUNGI— DISCOMYCETES 



179 



Fig. 73. — Himalayan morel,' 

 with section and sporidium. 



India a large leathery Fungus of the genus Midotis takes the 

 place of the species of Otidea found in Europe. 



The Fungi in this group which exercise a deleterious 

 influence on growing plants are limited in number, and con- 

 fined to two or three genera. It has been declared that a 

 small Peziza, under the name of Peziza 

 Willhommi, is the cause of the devas- 

 tating larch disease ; whereas we are 

 of opinion that it is really the same 

 as Dasyscypha clandestine/,, and is para- 

 sitic upon the diseased spots, caused 

 by resinosis, and is not the source of 

 the disease. More decided, however, 

 are the relations between the small 

 species of Pseudopeziza and the living 

 plants which they attack. One of these 

 is common on clover, another on 

 lucerne, and others on Caltha, Galium, 

 etc. All these are undoubtedly de- 

 structive, but outside this genus nearly all the leaf-species only 

 occur upon leaves subsequent to death or decay. A very 

 abnormal series of forms, most nearly related to the Biscomy- 

 cetes, and classed with them, are the occasion of peach blister, 

 the pear -leaf blister, and similar diseases. These Fungi of 

 the genus JExoascus have no proper excipulum, but consist of 

 naked asci, placed side by side on a kind of mycelium invest- 

 ing the blistered spots. 



It would be scarcely out of place to allude here to a few 

 species of the form of Peziza, but classed together under the 

 generic name of Sclerotinia, which are developed from fungoid 

 bodies called Sclerotia — which are a sort of compact mycelium 

 — and after a period of rest give rise to species of Peziza or 

 Sclerotinia. One of these is common on a Sclerotium found in 

 company with the roots of the wood anemone (Fig. 74). Another 

 is developed from a little black Sclerotium often common in the 

 haulms of potatoes and cabbage-stalks. Another, again, occurs 

 on a Sclerotium developed within the substance of rushes. 

 The injury to the plants is caused in the Sclerotium stage, but 

 the mature Fungus bears the common name of Sclerotinia. 



