THE FUNGI WHICH CAUSE PLANT DISEASE 



153 



B. polymorpha (Oed.) Wett.*-' *' is a common saprophyte on 

 bark. It is said to sometimes become parasitic. Ascocarps black, 

 stipitate; disk scarcely cupped, ranging up to 4 cm. in diameter 

 although usually smaller. 



Caliciaceae (p. 134) 



Stroma more or less thalloid, with or 

 without algal cells, often rudimentary and 

 inconspicuous; ascoma more or less globoid, 

 stipitate; the apex of the ascus dissolv- 

 ing before the spores are matured, thus 

 allowing the hyaline unripened spores to es- 

 cape and mature afterwards. 



This small family (less than one him- 

 dred twenty-five species) contains the only 

 lichens of phytopathological importance, un- 

 less the foliose lichens which sometimes ap- F'o- 109.— C. 



. . . , on Grape 



pear on poorly kept fruit trees be consid- 2, Ascua. 



1 Maaaee. 



ered. 



pallida 

 Root. 

 After 



Key to the Genera of Caliciacese 



Ascoma with a long stalk 

 Spores spherical, or subspherical 

 Spores colorless or only slightly colored. 1. Coniocybe, p. 153. 



Spores brown or brownish 2. Chsenotheca. 



Spores elongated, septate 

 Spores elongate elliptic or egg-shaped, 



usually two-celled 3. Calicium. 



Spores elliptic to spindle-form, 4 to 



&-celled 4. Stenocybe. 



Ascoma short stalked 



Spores 2-celled 5. Acolium. 



Spores globose, 1-celled 6. Sphinetrina. 



Coniocybe pallida (Pers.) Fr. is generally distributed through- 

 out Europe and America, commonly on the bark of various forest 

 trees and upon the crown and roots of the grape. The parasitic 



