A deciduous tree and shrub of the genus Salix, order Salicales, common along streams and in wet places in the United States, Europe, and China. The twigs are often yellow-green and bear alternate leaves which are characteristically long, narrow, and pointed, usually with fine teeth along the margins (see illus.). Flowers occur in catkins; the staminate consist of one to twelve (usually two) stamens, with one or two nectar glands; the pistillate have a single ovary of two carpels, with one to four small glands. The fruit contains several silky seeds. The species are wind- or insect-pollinated and hybridize freely, which often makes identification difficult.