THE FUNGI 



259 



335. Discussion. — The wheat rust is interesting to the 

 botanist on account of its singular variety of methods 

 of asexual spore formation. It is also of great practi- 

 cal importance, as it is a very dangerous enemy of the 

 grain farmer. Comparatively rust-proof species of wheat 

 are much in demand. Barberry bushes should never be 

 allowed to grow in whea1>raising regions, and in many 

 parts of England they have been nearly or quite exter- 

 minated by farmers. Where no barberries are found the 

 rust is carried from one 

 wheat crop to the next by f^7^^ 

 uredospores only. 



PSALLIOTA, ONE OF THE 

 BASIDIA FUNGI 



336. Occurrence. — The 

 common mushroom, Psal- 

 liota cam'pestris (often 

 known as Agaricus campes- 

 tris), grows in open fields 

 and pastures in the United 

 States and Europe. It is the mushroom most extensively 

 cultivated for market, and if not found in the field it may 

 be raised from " spawn " (mycelium), put up in the shape 

 of bricks and sold by seedsmen in the large cities. Those 

 who make a specialty of selling it furnish directions for 

 culture. A moderately warm cellar or basement makes 

 an excellent winter garden for mushrooms. 



There are many other gill fungi of frequent occurrence 

 besides the edible mushroom. Most of them are commonly 

 known as toadstools. Any of these may be collected for 



Ti 184 

 Ti in etes Pint a, 

 Babidia Fungus 



TLub spet-ies is parasitic on 

 coniferous trees and does 

 them much injury. 



