56 Minnesota Plant Life. 



shaped somewhat like clam shells, so that the whole plant-body, 

 often several inches in diameter, seems to be composed of nu- 

 merous white shells overlapping each other and all attached to 

 a common base. 



Prickle-fungi. The prickle-fungi at least some of them 

 might be mistaken for much branched forms of club-fungi ; but 

 they can be distinguished by the general downward tendency 

 of the branches, so that in a well-known species not uncommon 

 in the valley of the St. Croix where it grows upon decaying tree- 

 trunks, there is a coral-like aspect to the whole plant-body. 

 This variety is generally white, or slightly yellowish, or yellow- 



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FIG. 15. Growth of club-fungi on decaying wood. After I y loyd. 



ish-brown in color, often as large as a man's head, and made up 

 of a group of thick, irregular branches upon the under sides of 

 which great numbers of prickles half on inch or more in length 

 grow downward. Not all of the prickle fungi have exactly this 

 kind of a plant-body. Some of them outwardly resemble toad- 

 stools, and might be mistaken for them if one did not look upon 

 the under side where he would discover instead of the radiating 

 gills of the toadstool the whole under surface of the cap cov- 

 ered with a growth of prickles. Upon the surface of these 

 prickles the spores of the plant are developed, and by their co- 

 operation the fungus is able to maintain itself from year to year. 



