244 ENGLISH BOTANY. 
osier-beds in many places; this is the only form I know of occurring 
so far south. Local in Ireland. 
England, Scotland, Ireland. Shrub. Late Spring and early Summer; 
sometimes again in late Summer. 
S. nigricans is as variable a plant as S. phylicifolia, and runs through 
nearly a parallel series of variations. It is sometimes only 1 foot high, 
at other times 10 or 12 feet. The leaves also vary much, both in form 
and size, being sometimes little more than 1 inch long, at others 2 or 
3 inches, or even more. The points in which it differs from S. phylici- 
folia are the thinner texture of the leaves, which have the veins more 
impressed above and more prominent beneath, their colour .darker 
above and less intensely glaucous beneath, both sides often retaining 
their hairiness for a longer period; the young branches and young 
leaves are more thickly pubescent; the stipules are more often present, 
and always larger; the leaves, especially when young, have a greater 
tendency to turn black in drying; the capsule is more often glabrous, 
with a shorter style and longer pedicel. 
S, floribunda (Forbes) is a doubtful plant, of which the female seems 
to be unknown, but the thin hairy leaves and large stipules indicate that 
it is a form of S. nigricans rather than of S. phylicifolia, to which Dr. 
Walker-Arnott is inclined to refer it. 
Dark-leaved Sallow. 
French, Saule noircissant. German, Schwarzwerdende Weide. 
Group III].—INCUBACA. Linn. 
Style short; stipules linear. 
Small shrubs, with the pubescence of the leaves usually silky. 
SPECIES (?) XXII—S ALI X AMBIGUA. Livrh. 
Prare MCCCLV. 
Reich. Ic. Fl. Germ. et Helv. Vol. XI. Tab. DXCII. Fig. 1243, b, and 1243, ec. 
Anders. Mon. Sal. p. 117. Borver, in Engl. Bot. Suppl. No. 2733. Hook. Brit. Fl. 
ed. iv. p. 361. Hook. & Arn. Brit. FI. ed. viii. p. 404. Bab. Man. Brit. Bot. ed. 
vi. p. 314. 
S. aurita-repens, Wimm. Sal. Europ. p. 233. 
Leaves oblong-obovate or -oblanceolate or -oval or -elliptical, with a 
short recurved point, faintly crenate-serrate or serrate, sometimes — 
nearly entire, rugose, from the veins being impressed above and 
prominent beneath, dark green, shining and subglabrous, or grey or 
hoary and pubescent above; subglabrous and glaucous or more often 
clothed with silky or cottony hairs beneath. Stipules small, subsessile, 
