DISCOMYCETES. 



135 



species of the Discomycetes and contains forms of very different 

 habit. They grow upon dead wood, upon the ground, and upon 

 dung. A few are parasites. 



Order 1. Helotiaceae. Apothecia with waxy envelope of 

 colourless, or yellowish prosenchymatous cells. Chlorosplenuim 

 ceruginosum is found on decaying wood (particularly Oak and Birch), 

 to which it gives a green colour. Sclerotinia has sclerotia which are de- 

 veloped upon the host-plant and from which, after a period of rest, the long, 

 brown-stalked apothecia arise. S. ciborioides (S. trifoliorum, Fig. 128) is 

 parasitic on Clover ; S. sclerotiorum, on Daucus-roots, Phaseolus, etc. ; S. bac- 

 carum, on the berries of Vaccinium myrtillus; " Botrytis cinerea " is a common 

 parasite and is probably the conidial form of S.fuckeliana (Fig. 127). Helot ium 

 herbarum lives on dry plant stems. Dasyscypha willkommii (Fig. 129) produces 

 Larch -canker on the bark of the Larch. 



a- 



<t 



FIG. 128. Sclerotinia ciborioides : a sclerotium 

 with three apothecia slightly magnified; b nscus 

 with eight ascospores ; c germinating ascospore. 



FIG. 129. Dasyscyphav-illkommii: 

 a portion of bark of Larix decidua 

 with sessile, cup-shaped apothecia 

 (nat. size) ; b two paraphyses on 

 either side of an ascus with eight 

 ascospores. 



Order 2. Mollisiaceae. Mollida cinerea, principally on decaying wood. 



Order 3. Pezizacese. This order contains the largest and 

 morphologically the highest forms of the Discomycetes. Apothecia 

 fleshy, and in the later conditions generally saucer-shaped. 



Peziza, with sessile apothecia, growing on the ground ; P. cochleata is brown, 

 and coiled like a snail-shell ; P. coccinea is scarlet ; P. aurantia occurs as an 

 orange-coloured expansion on the ground. 



Order 4. Ascobolaceae. Apothecia fleshy ; in the later stages flat or 



