200 



The Willows 



Fig. i6i. — Large-leaved Alaskan 

 Willow. 



21. LARGE-LEAVED ALASKAN WILLOW — Salix ampIifoUa CoviUe 



This species is known only from Alaska, where it inhabits coastal sand-dunes; 



it forms either a shrub or a small tree, the largest 

 individuals recorded being about 8 meters high, 

 with trunks about 3 dm. in diameter. 



The young twigs are stout, densely hairy, and 

 remain more or less hairy for two or three years, 

 becoming purple. The leaves are oval to obovate, 

 8 cm. long or less, 4 to 6 cm. wide, blunt or short- 

 pointed at the apex, mostly rounded at the base, 

 finely toothed or entire-margined, white silky-hairy 

 on both sides when young, but becoming nearly or 

 quite smooth when very old; they have short hairy 

 stalks I cm. long or less. The catkins appear on 

 short, leafy branches of the season; they are 4 to 

 6 cm. long, 1.5 cm. thick, and flower in Jime, de- 

 veloping with the leaves; their bracts are dark 

 brown and persistent; the staminate flowers have 

 two stamens with smooth filaments, and the pistil- 

 late ones have a hairy-stalked, smooth, narrow ovary, a very slender style 2 to 4 

 mm. long, the deeply 2-lobed stigmas about i mm. long. The fruiting catkins be- 

 come 2 cm. thick and about 8 cm. long, the smooth, narrowly ovoid capsules 8 to 

 9 mm. long. 



22. HOOKER'S WILLOW — Salix Hookeriana Barrett 



Hooker's willow inhabits sand-dunes along 

 the coast from British Columbia to Oregon, 

 sometimes growing almost within the influence 

 of salt water. While often a shrub, it some- 

 times forms a tree up to 16 meters high, with 

 a trurfk 3 dm. thick or more. 



The thin, brown bark is slightly fissured, 

 the young twigs densely velvety-hairy, and re- 

 main more or less so during parts of two sea- 

 sons, becoming purple-brown and smooth; the 

 winter buds are hairy, pointed, about 5 mm. 

 long. The leaves are obovate to oblong-obo- 

 vate, bluntly finely toothed or entire-mar- 

 gined, blunt or short-pointed at the apex, 

 narrowed at the base, usually 5 to 8 cm. long 

 and 2 to 4.5 cm. wide, but those of strong 

 shoots sometimes 15 cm. long; they are very hairy when yoimg, and more or less 



Fig. 162. — Hooker's Willow. 



