stigmas and fuscous bracts ; it probably does not occur in 

 America. 



Type collected at Dawson by R. S. Williams, June n, 

 1899, a more mature specimen June 12. Also collected by 

 Seemann on Chamisso Island, 1851, no. 1783, and Kotzebue 

 Sound and Norton Sound, 1849, no - I 4 2 3* 



Family Betulaceae. 



Betula glandulosa Michx. Dawson (Williams) ; Ft. Sel- 

 kirk (Tarleton). 



Betula -papyri/era Marsh. Skagvvay. 



Betula resinifera (Regel) Britton. 

 B. alba subsp. verrucosa var. resinifera Regel, Bull. Soc. 

 Mosc. 18: 398. 1865. 



A white barked tree, sometimes 15 m. high, the trunk 

 reaching 3 dm. in diameter, the young twigs densely glandu- 

 lar-resiniferous. Leaves deltoid- ovate, acuminate, sharply 

 irregularly serrate, broadly cuneate, truncate, or some of them 

 cordate at the base, dark green above, pale, and when young 

 resinous-glandular beneath, glabrous, slender-petioled ; blades 

 5-8 cm. long, 4-7 cm. wide just above the base; petioles 

 1.5-2.5 cm. long; young staminate aments 2 or 3 together; 

 ripe pistillate aments slender-peduncled, cylindric, 3 cm. long, 

 1-1.2 cm. thick; pistillate scales about equally 3-lobed, the 

 middle lobe lanceolate, acute, the lateral ones obliquely ob- 

 long-obovate, obtuse, all 3 ciliate ; wings of the seed rather 

 broader than its body. 



Dawson, R. S. Williams, Aug. 13, 1899 (type); Ft. Sel- 

 kirk, J. B. Tarleton, no. 138, July 18, 1899. Specimens 

 in the National Herbarium, obtained by Miss E. Taylor on 

 Peel's River, July 14, 1892, and at Ft. Simpson in i860, no 

 collector indicated, are also referable to this species. 



Our material agrees in every respect with Regel's descrip- 

 tion in De Candolle's Prodromus, 16: Part 2, 164. 1868. 



The tree is evidently more closely related to the Old World 

 Betula alba than to either of the other American white-barked 

 species B. fafyrifera and B '. -popdifolia, and is an interest- 

 ing addition to our arboreous flora. 



