The Lapland Willow (Salix lapponum) is of a similar proportion to the last-named, sometimes erect, sometimes trailing. Its leaves are more elliptic in shape, covered above with silky hairs and below with cottony filaments. In lanata the raised veins form a network pattern; in lapponum they are straight. The stipules at the base of the long foot-stalk are small or altogether wanting. Like the preceding species, it is restricted to Scotch Alpine rocks, at elevations between 2000 and 2700 feet.
The Whortle-leaved Willow (Salix myrsinites) is a small, wiry, creeping, or half-erect shrub, six inches to a foot high, with toothed, dark glossy leaves, an inch or less in length, whose net-veining shows on both sides. It is restricted to the Alpine parts of mid-Scotland, from 1000 to 2700 feet.
The Small Tree-Willow (Salix arbuscula) is a small shrub, whose stem creeps along the ground and roots as it goes, sending up more or less erect branches a foot or two high. The downy twigs are first yellow, then reddish-brown. The small leaves vary from egg-shaped to lance-shaped, and are shining above and glaucous beneath; toothed. In the Highlands of Aberdeen, Argyll, Dumfries, Forfar, and Perth, between 1000 and 2400 feet.
The Least Willow (Salix herbacea) is not so restricted in its range, for it is found in all parts of the United Kingdom where there are heights sufficiently Alpine (2000 to 4300 feet) for its tastes. It is only an inch or two high, and has consequently the distinction of being the smallest British shrub. It is not so herbaceous as it seems, or as its name implies, for its shrubby stem and branches creep along underground, sending up only short, scantly leaved twigs. The curled, roundish leaves do not exceed half an inch in length; they are net-veined, toothed, and shining. The catkins appear after the leaves.
The Net-leaved Willow (Salix reticulata) is another of the Scotch Alpines. It is similar in habit to the last-named, but
larger, its buried branches sending up twigs a foot long. The roundish-oblong, leathery leaves are not toothed; they are smooth above and glaucous beneath, strongly net-veined on either side. The purplish or yellow catkins do not develop till after the leaves. It is restricted to the mountains of Aberdeen, Forfar, Inverness, Perth, and Sutherland.
The Weeping Willow (Salix babylonica), so conspicuous an ornament of riverside lawns, is an introduced species, whose slender branches hang downwards. It has large, lance-shaped, finely toothed leaves, smooth above and glaucous beneath. Further description of so well-known a tree is unnecessary. It attains a height of forty to fifty feet. The name babylonica was bestowed in the belief that its headquarters were on the banks of the Euphrates. It is now known to be a native of Japan, and other parts of Asia.
The name Willow is the Anglo-Saxon welig, indicating pliancy, willingness.