18 



removes all doubt. For distinctions between species of Nephroma, 

 see A^. resupinatum. 



Nephroma laevigatum Smooth Swiss Lichen 



A subspecies differing from A'', helveticum in the absence of 

 marginal or other growths from the upper surface, and of most 

 of the down from the under. This lack makes it even more diffi- 

 cult to recognize, yet one already familiar with N. helveticum 

 can name it at once. It should be studied in connection with that 

 subspecies. There are also intermediate forms. 



Nephroma parile. Powdery Swiss Lichen 



A subspecies of A^. resupinatum resembling N. laevigatum but 

 -with whitish, dusty soredia along the margins and clustered on 

 the upper surface. This is the only local Nephroma having soredia. 

 Found on trees in the north, perhaps not within the New York 

 area. 



{Group 7 to be continued) 



Ridge WOOD, N. J. 



BOOK REVIEWS 



Trees of the South* 



Arthur Harmount Graves 



The situation with regard to books about trees seems to be 

 similar to that concerning text books of botany. It would seem 

 that every botanist who is anybody has written, is writing, or will 

 write a text book of botany. And everyone knows that the books 

 about trees are legion. And yet, as the Book of books says, "Of 

 the making of many books there is no end."^ I have always taken 

 this as meaning not a countless repetition of the same old thing, 

 Tjut that new, and ever new, outlooks, new treatments of the subject 



* Trees of the South. Green, Charlotte Hilton. Univ. of North Carolina 

 Press, Chapel Hill, N. C. 551 p. $2.50. 

 ^ Ecclesiastes 12.12. 



