8o 



TEXTBOOK OF BOTANY 



cap is hemispherical at first, later flattened but with a slightly 

 bulging center. The vegetative threads penetrate the bark 

 of the roots of living trees, especially of some of the cone- 

 bearing trees, and between the bark and the wood they mass 

 together into flat strands that grow upward into the trunk 

 as well as through the roots. From these strands, separate 



ABC 



Fig. 37. — Poisonous mushrooms: A, Amanita verna; the main portion 

 of the fruiting body emerging from the egg-shaped structure which com- 

 pletely enclosed it at an earlier stage ; a part of this enclosing structure 

 remains in the form of a cup at the base of the stalk. B, a mature fruiting 

 body of Amanita pantherina. C, a somewhat younger fruiting body of the 

 latter species cut lengthwise, showing the ring still attached to the edge of 

 the cap. Photographs by E. T. Harper. 



threads grow into the bark and wood, whose cells are de- 

 stroyed (rotted) by the fungus ; in time the tree is Idlled. 

 By means of other strands which penetrate the soil for long 

 distances, the fungus spreads from tree to tree. The strands 

 can also live s&prophytically in the soil or in the dead wood 

 at the bases of stumps. Thus the honey mushroom is a widely 

 spread saprophyte as well as one of the most dangerous 



