THALLOPHYTES— FUNGI 



281 



highly colored. They ai'ise from saprophytie mycelium and are 

 lined with the upright tubular asci and their paraphyses. Many 

 of them are highly colored and very interesting but of little or 

 no economic importance. 



The genus Sclerotinia contains a number of parasitic species 

 that are very destructive to agricultural crops. One of the most 

 important is 8. cinerea, which cause the brown rot of the peach. 

 The mycelium grows within the fruit and produces the great 

 mass of chain-like spores on the surface. Under some conditions, 



FiQ. 130. — Fruiting body of mildew. 



FxG. 131. — Peziza. 



the mycelium of the fungus within the old fruits on the ground 

 produces a cup'-like growth containing great numbers of asci. 



The genus Morchella contains some of the large edible fungi. 

 One of the most common species is M. escvlenta, which is known 

 as the common spring morel and is considered a great delicacy. 

 The large convoluted top is the ascocarp, which, of course, bears 

 the paraphyses and the asci containing eight spores each. 



The Lichens constitute a peculiar group of plants which are 

 usually included in the Ascomycetes. They grow on rocks, soil, 

 tree trunks, old fences and in festoons from the branches of tree®. 

 Each lichen consists of a mass of algje (usually unicellular) 

 which has been parasitized by a fungus. These fungi (with two 



