16 FOREST TREES OF NORTH AMERICA. 



Castanea is represented by two species iu the Atlantic region. 



Fagua, Ostrya, and Carpinus are each represented by a single widely-distributed species in the Atlantic region. 



Betula, with its center of distribution in the northern Atlantic region, is represented by one arborescent and 

 by one frutescent species common to the Atlantic and the Pacific regions, by four arborescent and one frutescent 

 species in the Atlantic region, and by one arborescent species in the Pacific region. 



Alnu8 is represented by three arborescent species in the Atlantic, of which one extends to the Pacific region, 

 by three arborescent species in the Pacific region, and by two frutescent species common to the Atlantic and the 

 Pacific regions. 



Salix is represented in the Atlantic region by five arborescent species, of which three are found in the Pacific 

 region, and by many frutescent species. This genus is represented in the Pacific region by ten arborescent and 

 by many frutescent species. 



Populu8 is represented by two species common to the Atlantic and the Pacific regions, by three species in the 

 Atlantic region , and bj- three siiecies in the Pacific region. 



Libocedrus is represented by a single species in the Pacific Coast region. 



Thuya is represented by one species in the Atlantic and by one species in the Pacific region. 



Chamcecyparis is represented by one species in the Atlantic and by two species in the Pacific Coast region. 



Cupressus is represented by four species in the Pacific region, of which three occur in the coast and one in the 

 Mexican region. 



Juniperus is represented by one arborescent species in the Atlantic region, by three arborescent species in the 

 Pacific, of which one belongs to the Pacific-Mexican and one extends to the Atlantic-Mexican region, and by two 

 frutescent species common to both regions. 



Taxodium is represented by a single species in the southern Atlantic region. 



Seqtioia, an endemic genus of the Pacific Coast region, is there represented by two species. 



Taxus is represented by an exceedingly local arborescent species in the southern Atlantic region, by a frutescent 

 species in the northern Atlantic region, and by an arborescent species in the Pacific Coast region. 



Torreya is rei)resented by a single exceedingly local arborescent species in the southern Atlantic region and by 

 a single species iu the Pacific Coast region. 



Pinus, with its center of distribution in the southern Pacific Coast region, is represented by thirteen species 

 iu the Atlantic and by twenty-two species in the Pacific region, of which three belong to the interior and four to 

 the Mexican region. 



Picea is represented by one species common to the Atlantic and the Pacific regions, by one species iu the 

 Atlantic, and by three species in the Pacific region, of which one belongs to the interior region. 



Tnuga is represented by two species in the Atlantic and by two species in the Pacific region. 



Pneudoisuga, an endemic genus of the Pacific region, is there represented by a single widely-distributed species. 



Abies is represented by one widely-distributed and by one exceedingly local species in the Atlantic region and 

 by seven species in the Pacific region, of which one is exceedingly local. 



Larix is represented by one species in the Atlantic and by two species in the Pacific region. 



Sabal is represented by a single species in the southern Atlantic region. 



Washingtonia is representert by a single species in the Pacific Mexican region. 



Thrinax is represented by two semi-tropical species, and Oreodoxa by one. 



Yucca is represented by one arborescent and one frutescent species common to the Atlantic and the Pacific 

 regions, by one arborescent and by two frutescent species in the Atlantic, and by two arborescent and by one 

 frutescent species in the Pacific region. 



