THE SUGAR MAPLES, WITH A WINTER SYNOPSIS OF ALL 



NORTH AMERICAN MAPLES. 



BY WILLIAM TRELEASE. 



1 



North American botanists generally recognize one eastern 

 species of sugar maple with a well-marked variety, one in 

 the Gulf States, and a third species in the mountains of the 

 Southwest. Each of these is so variable as to weaken the 

 lines of specific separation, and in the last treatment of the 

 maples by an American botanist* they are all united as forms 

 or varieties of a single species. In contrast with this con- 

 servatism, European botanists are disposed to increase the 

 number of separable species. Pax,f in his monograph of 

 the genus Acer, recognizes three species of his group 



S 



the eastern and southern sugar 



maples, while the southwestern species is maintained ii 

 group Campestria. Wesmael,J in a later review of the 

 genus, follows Pax in keeping the southwestern species apart 

 from the group Saccharina. of which latter he reooo-nizps 



ponding to the 



other two species admitted by Pax. Quite 

 Schwerin, in an enumeration of the maples from a horti- 

 cultural standpoint^ carries the separation of forms even 

 further than Pax, since he maintains all of the species ad- 

 mitted bj' the latter, while he recognizes three varieties and 

 seven named forms of the northern sugar maple. 



I was led by these publications to make an examination 

 of the material in the herbarium and arboretum of the 

 Missouri Botanical Garden and in Tower Grove Park, and 



, * Sargent, Silva of North America, ii. 1891, 97. 

 t Engler's Bot. Jahrbucher, 1886, vii. 241, and 220. 

 t Revue critique des especes du genre Acer 

 § Gartenflora, 1893, xlii. 455. 



Reprints issued Jan. I, 18<t4. 



60-61 



1 



