The Crack Willow or Withy (_Salix fragilis_) is one of the two most considerable of our tree Willows. In good soil it will in twenty years attain nearly its full height, which is eighty or ninety feet. Its bole sometimes has a girth of twenty feet. Its smooth, polished shoots afford the best ready means of distinguishing it, for instead of their base pointing to the centre of the trunk as in other trees, they grow obliquely, so that the shoots frequently cross each other. They are both tough and pliant, but if struck at the base they readily break off. This character explains the names Crack Willow and _fragilis_. The leaves are lance-shaped, three to six inches long, smooth, with glandular teeth, pale or glaucous on the underside, and with half-heart-shaped stipules, which, however, are soon cast off. As we have already indicated under the head of Poplars, the male and female catkins of the Willows are borne by different trees. In the case of the Crack Willow, the male catkins are an inch or two long, proportionately stout, each flower bearing two stamens (occasionally three, four, or five). The female catkin is more slender, the flowers each containing a smooth ovary, ending in a short style that divides into two curved stigmas. The catkins appear in April or May. Although, like most of the Willows, this species is fond of cold, wet soil in low situations, it is not restricted to the plains. In Northumberland it is found at 1300 feet above the sea. Its northward range extends as far as Ross-shire, but it is a doubtful native in both Scotland and Ireland. [Illustration: Crack Willow.] The Bedford Willow (_S. russelliana_) is believed to be a hybrid between _S. fragilis_ and _S. alba_. It grows to a height of fifty feet, with a girth of twelve feet. The leaves are more slender than those of _S. fragilis_, taper to a point at each end, and are very smooth on both sides. It occurs in swampy woods. [Illustration: _Pl. 62._ White Willow--summer.] [Illustration: _Pl. 63._ Flowers of White Willow.] [Illustration: White Willow.]