268 FORESTS AND TREES OF NORTH AMERICA. 



EXPLANATION OF THE MAP. 



This outline map of tbat part of America nortli of Mexico is in- 

 tended to illustrate, so far as can be done on so small a scale, the 

 distribution of forests, trees, &c., according to the results of the latest 

 explorations and studies. In order to get it within the size of the 

 page it was found necessary to make the principal meridian oblique 

 to the sides of the map, but by noticing the corresponding numbers of 

 the degrees of latitude the reader will easily perceive the true direc- 

 tion of the several points, east and west being, of course, nearly at 

 right angles to the meridian. The equatorial projection is preferred, 

 as showing best the true area of the various regions. The dark full 

 lines crossing the continent are the outlines of the best determined 

 and most important natural divisions, which may be called natural 

 PROVINCES. The broken lines represent approximately the subdivi- 

 sions of these provinces, called regions, and also parts of the province 

 boundaries not accurately determined. 



The undulations of surface, mountains, and other circumstances 

 cause great irregularities in the outlines of regions, especially in the 

 western part of the continent ; but these are neither well determined 

 nor, if they were, are they capable of illustration on this scale. It is 

 believed, however, that the most marked limits are represented, that 

 is, those by which the greatest number of species, both of plants and 

 animals, are bounded in their range. 



In using this map the reader should compare it with a good and 

 large map of North America. The regions in which trees are found 

 (indicated by letters on the map) are : 



A. The Algonquin, in which four or five species of trees seem to 

 be more abundant than elsewhere, and therefore characl eristic ; 

 none, however, are peculia7\ - - - - - 5 



B. The Athabascan, in which about twelve are characteristic but 

 none peculiar - - - - - - 12 



C Canadian, having seventeen characteristic trees and one appa- 

 rently peculiar - - - - - - -18 



D. Alleghany, in which there are twenty-four trees characteristic 

 and six peculiar - - - - - - 30 



E. Ohio, having twenty-two characteristic and one peculiar - 23 



F. Tennesseean, with thirty-four characteristic and three peculiar 37 



G. Carolinian, with eighteen characteristic and seven peculiar - 25 

 H. Mississippian, with thirty-two characteristic and seven pecu- 

 liar - ■• - - - - - - 39 



I. Floridian, with about thirty-two characteristic and thirteen 

 peculiar - . - - - - - 45 



Total number of species in the eastern forest regions - - 234 



D, E, F, G, H, may be considered as forming a natural province, 

 and called the Apalachian. Florida appears rather to belong to the 

 West Indian province. 



