(165 ) 
stigmas and fuscous bracts; it probably does not occur in 
America. 
Type collected at Dawson by R. S. Williams, June 11, 
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. 1423. 
Family BETULACEAE. 
Betula glandulosa Michx. Dawson (Williams); Ft. Sel- 
kirk (Tarleton). 
Betula papyrifera Marsh. Skagway. 
Betula resinifera (Regel) Britton. 
B. alba subsp. verrucosa var. resintfera 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, 
I-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 1860, 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. papyrifera and B. populifolia, and is an interest- 
ing addition to our arboreous flora. 
