220 



LARGER FORMS OF ASCOMYCETES 



forming a cup-like structure resembling that shown in Fig. 156. 

 A section through one of these cups reveals the asci intermingled 

 with hyphae, also called paraphyses, in the form of a layer or 

 stratum. Such an association of spore-bearing organs and para- 

 physes is called a hymenium. The spores are discharged to con- 

 siderable distances, owing to the accumulation of fluids in the 

 asci which finally rupture at their apices. In some forms, the 

 entire ascus is discharged with an audible explosion, owing to 

 the swelling and rupture of the supporting hyphae. The bright 

 scarlet cups of Sarcoscypha, common in the spring on decaying 

 sticks and the gray cups of Peziza growing upon the ground 

 and decaying wood, are familiar examples of the order. 



92. Order h. Helvellales. These are fleshy forms in which 

 the hymenium is exposed over the surface of a variously shaped 

 ascocarp, as shown in the common genera illustrated in Fig. 

 158. The morel or Morchella, in which the hymenium is spread 



FIG. 158. Common forms of the Helvellales : A, the morel, Morchella, 

 surface view at left and in section at right. The asci and paraphyses form 

 a hymenium over the honeycomb surface. B, Leotia, a small gelatinous 

 form of a light, bluish-green color. C, Geoglossum, a black tongue-like 

 form. In B and C the hymenium is confined to the upper enlarged portion 

 of the fungus. Both are common in boggy ground. 



over the pitted or honey-combed surface of the ascocarp, is one 

 of the most highly prized of the edible fungi. The members of 



