238 BOTANICAL GAZETTE [march 



assumed slightly different forms in different parts of the country. 

 In what is considered the typical species, which occurs in the region 

 east of the Rocky Mountains, the united part of the samaras of the 

 fruit is more or less constricted at the base into a short stipe, and 

 on the more western forms this constriction usually does not occur. 

 This constriction and its absence, together with the absence or 

 presence of pubescence on the leaves and branchlets, have some- 

 times been used to separate A. Negundo into several species, but 

 the characters on which these species have been based are not 

 particularly important, and it seems better to treat A . Negundo as 

 a species with a number of varieties which often intergrade, for the 

 characters on which they are based are not always constant. 



In what is considered the typical species the branchlets are green 

 and glabrous; the leaves are usually 3-foliate but occasionally 

 5-7-foliate; the leaflets are ovate to elliptic or oblong-obovate, 

 acuminate and often long-pointed, rounded or cuneate and often 

 unsymmetrical at base, coarsely and irregularly serrate usually only 

 above the middle, and occasionally slightly lobed, slightly pubescent 

 above and more or less tomentose below when they unfold, and at 

 maturity glabrous above, usually villose-pubescent along the under 

 side of the midribs and veins, and often furnished with conspicuous 

 tufts of axillary hairs, otherwise glabrous or slightly pubescent 

 below. 



The typical form is distributed from western New England and central 

 New York to Minnesota, Iowa, and Missouri, and southward to central 

 Florida, northern Alabama, western Louisiana, and eastern Texas. I have 

 not seen specimens of wild trees from eastern New England, eastern New York, 

 New Jersey, or Delaware. The box elder is common along the St. Lawrence 

 River near Montreal and in eastern Ontario, but these trees are believed to 

 have been naturalized in recent years. As here considered it passes into the 

 following varieties: 



Acer Negundo var. violaceum Kirchner in Kirchner and 

 Petzold Arb. Mosc. 190. 1864. — Ruhac Nuttallii Nieuwland, Am. 

 Middl. Nat. 2:137. 191 1. — Negundo Nuttallii Rydberg, Bull. 

 Torr. Bot. Club 40:55. 1913.— This variety is distinguished by its 

 rather stouter, pale or bluish violet branchlets covered with a 

 glaucous bloom, rather larger buds, and usually 3-7-foliate leaves 



