and Old World Birches. 177 



left standing, after the widespread devastation of forest fire, 

 by the Wassataquoik River, near Mt. Katahdin, in Maine, is 

 conspicuous on account of its pendulous " weeping " branches, 

 small leaves and essentially straight peduncles. Though in 

 habit this tree is strikingly like B. pendida, its leaves place it 

 nearer B. alba. In fact, the material matches perfectly a 

 specimen sent to the Gray Herbarium by Kegel, from Finland, 

 of B. alha, var. ghctinosa, Trautv.,"^ thQiovm pendula\ figured 

 by Reichenbach (Ic. Fl. Germ., xii, t. 625) as B.pendida^ 

 though not the species of Roth. This Wassataquoik Yalley 

 tree may be known as Betula alba., var. gluthiosa, Trautv. 

 This form {B. glutinosa., Wallr.:}:) is treated by various Euro- 

 pean authors as a natural hybrid between B. alba {pid)escens) 

 and B. peiuhdxi^^ but the apparent absence from Maine of 

 B, pendida renders this origin of the tree improbable. 



Betula alba, var. cordifolia. 



Another tree more common in the mountainous portions of 

 ^ew England than Betula alba, var. glutiyiosa, differs from 

 the ordinary Canoe Birch only in its cordate-ovate leaves. In 

 this character it is very constant, however, and seems to de- 

 serve the varietal recognition given it by Regel as B. alba, 

 ^\xh^^. pajpyrifera, /S, cordifolia, \ (B. cordifolia, Regel, Mon. 

 28, t. 12, figs. 29-36). The species, B. cordifolia, was based 

 upon one of de la Pylaie's specimens from Newfoundland, and 

 in his later treatment of the tree Regel cited two sheets in the 

 Gray Herbarium, one from Mt. Katahdin, Maine, the other 

 from Lake Superior. The tree is common on the upper 

 wooded slopes of Katahdin and other mountains of northern 

 New England, becoming a dwarf shrub at their summits, where 

 it has passed as B. jKijyyracea, var. minor, Tuck. Tucker- 

 man's original material and description, however, was of 

 another form soon to be noted. The tree or shrub of the 

 mountainous districts of New England, with cordate leaves, 

 pnbescent on the veins beneath, may be known as Betida alba, 

 var. cordifolia (Regel). Its range is a broad one, from north- 

 ern Labrador (6^ A. Kenaston, sheet No. 25,240, U. S. Nat. 

 Herb.) and Newfoundland to New Brunswick, Maine, the 

 White Mountains, New Hampshire, Lake Superior, Iowa 

 {B. Fink, No. 109), Alberta, British Columbia, Idaho, and 

 AVashington. 



* Trautv. ex Regel, Mon. Bet. (1861), 20. f Kegel, 1. c, 23. 



t Sched. Crit., 497(1822). 



?5 See Koehne, Detitscli Dendr., 109 ; Guerke, 1. c, 48. 



II Regel in DC, 1. c, 166. 



