130 THE FLORA OF THE ALPS 



The very numerous species of Willow present great 

 difficulties, owing to the minute characters which sepa- 

 rate them, and their tendency to hybridise. There are a 

 large number of alpine or sub-alpine forms, viz. : — 



A. Catkins lateral on the shoots of the previous year, 

 stalked or sessile ; ovary distinctly stalked : — 5. nigricans, 

 Sm. (including Mielichhoferi, Saut.); catkins on leafy 

 stalks, leaves dark green above, bluish-green beneath, 

 becoming black when dry, style often very long; wet 

 places. 6". hastata, L. ; scales of catkins covered with 

 long white silky hairs, leaves green or bluish beneath ; 

 rocks at a high elevation ; Switzerland, Dauphiny, Pyre- 

 nees, rare. S. myrtilloides, L. ; style very short, leaves 

 elliptic - lanceolate or obovate, stipules cordate-ovate; 

 Upper Bavaria. S. grandifolia, Ser. ; style o, leaves 

 downy, glabrous when old, up to 5 in. long ; a shrub 3-6 

 ft. high ; Alps, Jura, frequent. 5. pubescens, Schleich. 

 {albicans, Bonj.) ; a shrub not more than 3 ft., with 

 knotted branches, leaves very hairy ; high ; Vaud, Valais 

 (Rhone Glacier), Tirol. 



B. Catkins as in the last ; ovary very shortly stalked 

 or sessile : — 5. glabra, Scop. ; catkins cylindrical, on short 

 leafy stalks, scales pink at the tip, leaves broadly lanceo- 

 late, crenate or serrate, bluish-glaucous beneath, ovary 

 glabrous, style long; high, frequent. 6'. ccesia, ViU. ; 

 catkins smaller, style short, leaves entire; very high, 

 local. 6". repens, L. ; leaves small, lanceolate or elliptic, 

 silvery white beneath, stipules lanceolate; peat-mosses; 

 Switzerland, Jura, Tirol, Lombardy. ^. Arbuscula, L. 

 Qnclnding fcetida, Schleich., and Waldsteiniana, Willd.); 

 stem erect, leaves broadly lanceolate or elliptic, light- 

 green or grey-green beneath, catkins stalked, slender, 



