This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
The Willow family, to which the Osier belongs, is, like the Brambles, a difficult group even for the botanist, and he is a bold man or a very clever one who undertakes to identify specimens off-hand. They have suffered much at the hands of the "splitter." Hooker gives the number of British species as eighteen, with a considerable number of varieties; but by Babington many of these varieties are given specific rank, and his list of species runs to fifty-eight. It would, of course, be absurd for us to attempt in this restricted space to give a key even to Hooker's list; but our details of the flower structure, etc., will be found to apply in the main to all willows, and for a knowledge of the other species our readers must refer to Hooker. It should be added that, to increase the difficulties of the botanist, the plants that bear male flowers as a rule differ considerably from those that produce female flowers; for with scarcely an exception each plant is of one sex only.
The Osier (S. viminalis) is one of our most common species, and is the one most generally used for basket-weaving. It is a large shrub or low bushy tree, growing in wet places beside rivers and pools, or more frequently in Osier-beds. When allowed to grow uncut it attains a height of twenty or thirty feet; its long, smooth, and straight branches well furnished with very narrow leaves, tapering to a fine point, and sometimes nearly a foot in length. The margins of the leaf are quite free from teeth or lobes, and are curled back on the shining white silky underside. Both male and female flowers form catkins: the males each consisting of a hairy scale, to which are attached two stamens; the females of a similar scale bearing the ovary. The catkins appear before, the leaves, in March or April. Salix is the old Latin name for Willows and Osiers.