290 United States Species of Lycoperdon, 



Puff-balls rarely make their appearance in the early 

 part of the season. Old effete specimens of the preceding 

 autumn maybe found in early spring flattened and closely 

 pressed to the ground by the snows of winter. Fresh 

 specimens rarely appear before the middle of June. Their 

 greatest abundance is in late summer and early autumn. 

 During the months of August, September and October, 

 most of our species occur. One species I have found in 

 July and August only, another in July only. Some spe- 

 cies are invariably found in cleared lands, others in woods 

 or bushy places, while a few are denizens of both field and 

 forest. Some grow on the ground only, others on olrl logs 

 and decaying wood and a few on both the ground and de- 

 caying wood. One southern species is said to inhabit the 

 bark of living oak trees. Some species have distinct 

 whitish root-like fibres at the base. These penetrate the 

 earth and sometimes creep through it for a considerable 

 distance. In the Pear-shaped puff-ball they are generally 

 well developed, and sometimes several individuals are 

 found to be attached together by these creeping subter- 

 ranean fibres. 



In the determination of the species it is desirable to 

 have specimens in both the mature and the immature con- 

 dition. The former will afford the means of ascertaining 

 the color and character of the capillitium and spores, the 

 latter will exhibit the color of the immature plant and the 

 character of its warts or adornments. The character of 

 these and the characters of the capillitium and spores are 

 of the first importance, but the color of the immature plant 

 and its size and shape are less constant and reliable, and 

 are therefore generally considered of secondary import- 

 ance. Specimens preserved entire, and in their natural 

 shape are much more satisfactory for study than those 

 that are sliced in sections or pressed flat and mounted on 

 herbarium paper. Such entire specimens can easily be 



