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:—S. nzgricans, 
Sm. (including JZzeléchhoferz, Saut.); catkins on leafy 
stalks, leaves dark green above, bluish-green beneath, 
becoming black when dry, style often very long; wet 
places. S. Aastata, 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. grandzfolta, Ser.; style o, leaves 
downy, glabrous when old, up to 5 in. long; a shrub 3-6 
ft. high; Alps, Jura, frequent. S. 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 :—.S. g/abrva, 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. SS. cesza, Vill.; 
catkins smaller, style short, leaves entire; very high, 
local. S. repens, L.; leaves small, lanceolate or elliptic, 
silvery white beneath, stipules lanceolate; peat-mosses ; 
Switzerland, Jura, Tirol, Lombardy. S. Arduscula, L. 
(including fetida, Schleich., and Waldstecniana, Willd.) ; 
stem erect, leaves broadly lanceolate or elliptic, light- 
green or grey-green beneath, catkins stalked, slender, 
