Japanese name: コマイワヤナギ（駒岩柳） Scientific name:Salix rupifraga
A small deciduous shrub 0.5–1 m tall, growing on rocky cliffs in mountainous regions.
It is dioecious.
The branches fork rather densely and spread sideways; the current year's branches are densely covered with white hairs, which later become sparse.
The leaves are simple and alternate, oblong, 6–10 cm long and 2–3 cm wide, with a pointed tip and wavy serrations on the margin.
There are 6–9 pairs of lateral veins, which protrude on the underside.
Young leaves are densely covered on both sides with long soft hairs lying flat against the surface, and the hairs on the underside remain even when the leaves mature.
The petiole is 6–9 mm long, and stipules are rarely present.
The flowers are densely arranged on cylindrical catkins that appear as the leaves unfold, with several leaves at the base.
The male catkins are 2.5–4.5 cm long and 6 mm in diameter; the catkin stalk is about 4 mm long and densely covered with long white soft hairs.
The female catkins are 1.7–2.5 cm long and 5 mm in diameter; the catkin stalk is about 0.5 mm long and hairless.
The flowers have no petals.
