326 COVILLE 



places in the tundra. The plant is confined to the truly Arctic zone 

 on the islands and shores of the northern part of Bering Sea, the orig- 

 inal specimens having been collected by Chamisso and Eschscholtz, 

 botanists of the Kotzebue Expedition, in 18 16, at St. Lawrence Bay, 

 on the Siberian side of Bering Strait, about latitude 

 6s° 40'. 



Specimens have been examined as follow^s : 

 jPort Clarence. — Abundant on the tundra of the 

 mainland at the landing place of the expedition, 

 Coville and Kearney (Nos. 1877, ^^7^? 1S79), Tre- 

 lease and Saunders (No. 3472), Cole. 



St, Lawrence Island. — Found sparingly on the 

 tundra at Northeast Cape, Coville and Kearney (No. 

 3003). The plant w^as also collected on this island 

 Fig. 23. Sa- ]^y Chamisso and Eschscholtz, according to Ledebour, 



and by Kiellmann, of the Vesra Expedition. 

 Anders., a . . ^ ^ • 



mature leaf Siberian Coast. — Collected at Plover Bay by W. H. 



natural size. Dall, of the Western Union Telegraph Expedition, in 



1S65-6. 

 This species is easily distinguishable from the other prostrate willow^s 

 of Alaska by the form and serration of its leaf-blades. These are 

 commonly 1.5 to 3 cm. in length, narrowly obovate to nearly or- 

 bicular, apiculate, broadly acute or rounded at the apex, and either 

 glaucous or shining beneath. The catkins, which stand erect on leafy 

 peduncles, are a centimeter or a little more in diameter and commonly 

 3 to 6 times as long. In most of the specimens the capsules are dis- 

 tinctly but not densely pubescent, but in some they are smooth. The 

 style is about a millimeter in length. 



15. SALIX ARCTICA Pallas. Arctic Willow. 



Plate XL. 



Salix arctica Pall. F1. Ross, i^ : 86. 1788. 



Salix diplodiciya Trautv. Nouv. Mem. Soc. Nat. Mosc. 2 : 307. t. 14. 



1832. 

 Salix crassipdis Trev. ; Trautv. Nouv. Mem. Soc. Nat. Mosc. 2 : 308. /. 



13. 1832. 

 Salix pallasii Ki^'D'E^S. in DC. Prod, i^" : 285. 1868. 



The commonest and the largest of the prostrate v^dllows of Alaska. 

 Its short half buried trunk is sometimes 2 to 3 cm. in diameter, and sends 

 out stout horizontal creeping branches sometimes a centimeter thick at 

 the base. Its leaf blades are normally about 2.5 to 4 cm. long, obovate, 

 obtuse at the apex, tapering at the base, glaucous beneath, entire, or 



