CHAPTER XII. 



ASCOMYCETES SPORE-SAC FUNGI. 



Ascomycetes is from two Greek words : ascos, a sack ; mycetes, a fungus or 

 mushroom. All the fungi which belong to this class develope their spores in small 

 membranous sacs. These asci are crowded together side by side, and with them are 

 slender empty asci called paraphyses. The spores are inclosed in these sacs, 

 usually eight in a sac. They are called sporidia to separate them from the Basid- 

 iomycetes. These sacs arise from a naked or inclosed stratum of fructifying 

 cells, forming a hymenium or nucleus. 



Family Helvellaceae. 



Hymenium at length more or less exposed, the substance soft. The genera 

 are distinguished from the earth-tongues by the cup-like forms of the spore body, 

 but especially by the character of the spore sacs which open by a small lid, instead 

 of spores. The following are some of the genera : 



Morchella . . . Pileus deeply folded and pitted. 



Gyromitra. . .Pileus covered with rounded and variously contorted' folds. 



Helvella .... Pileus drooping, irregularly waved and lobed. 



Morchella. Dill. 



Morchella is from a Greek word meaning a mushroom. This genus is easily 

 recognized. It may be known by the deeply pitted, and often elongated, naked 

 head, the depressions being usually regular but sometimes resembling mere fur- 

 rows with wrinkled interspaces. The cap or head varies in form from rounded 

 to ovate or cone shape. They are all marked by deep pits, covering the entire 

 surface, separated by ridges forming a net-work. The spore-sacs are developed 

 in both ridges and depressions. All the species when young are of a buff-yellow 

 tinged with brown. The stems are stout and hollow, white, or whitish in color. 



The common name is Morel, and they appear during wet weather early in 

 the spring. 



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