514 



MUSHROOMS. EDIBLE AND OTHERWISE 



Urnula craterium. (Schw.) Fr. 



Urnula means burned; craterium means a small crater; hence the translation 

 is a burned-out crater, which will appear to the student as a very appropriate 

 name. It is a very common and conspicuous Ascomycetous, or cup fungus, 

 growing in clusters on rotten sticks that lie in moist places. When the plants 

 first appear they are small, black stems with scarcely any evidence of a cup. In a 

 short time the end of the stem shows evidence of enlargement, showing lines 

 of separation on the top. It soon opens and we have the cup as you see it in 

 Figure 438. The hymenium, or spore bearing surface, is the interior wall of the 

 cup. The cup is lined inside with a palisade of long cylindrical sacs, each con- 

 taining eight spores with a small amount of liquid. These sacs are at right 

 angles to the inner surface, and are provided with lids similar to that of a 

 coffee-pot ; at maturity the lid is forced open and the spores are shot out of 

 these sacs, and, by jarring the fungus when it is ready to make the discharge, they 

 can be seen as a little cloud an inch or two above the cup. Place a small slip of 

 glass over the cup and you will see spores in groups of eight in very small drops 

 of liquid on the glass. This species appears in April and May, and is certainly 

 a very interesting plant. It is called by some Peziza craterium, Schw. 



Helotium. Fr. 



Disc always open, at 

 first punctiform, then 

 dilated, convex or con- 

 cave, naked. Excipulum 

 waxy, free, marginate, 

 externallv naked. 



Figure 439. Helotium citrinum. Disc-fungus, yellow growing on 

 rotten logs. Slightly magnified. 



Helotium citrinum. Fr. 



Lemon-Colored Helo- 

 tium. 



This is a beautiful 

 little Disc-fungus, yel- 

 low, growing upon rot- 

 ten logs in damp woods. 

 They often grow in 



