46 THE BOOK OF NATURE STUDY 



met with in Britain, and almost any of them will serve for study 

 in the light of the description of one species. The following de- 

 scription may therefore be made somewhat general, but we shall 

 take as our special example a very common species, the Goat 

 Willow (Salix caprea) , which is also known as the Sallow. This can 

 easily be recognised by the fact that its flowers appear early in the 

 spring before any leaves are on the tree. The shoots bearing the 

 catkins are often worn on Palm Sunday in England. All the 

 Willows are trees or shrubs. Some are large trees, and even the 

 very small forms found high up on the British mountains, though 

 only an inch or two in height, are perennial woody plants. The 

 Goat Willow is a large shrubby plant or small tree reaching a 

 height of between thirty and forty feet. It usually grows near 

 water. The plant will first attract attention and be studied 

 when it flowers in April or May, and for its proper study twigs 

 bearing catkins must be collected from two distinct trees, since the 

 staminate and pistillate flowers are borne on distinct individual 

 plants. When the flowers are open the stout male catkins, of a 

 bright yellow colour owing to the projecting stamens, are readily 

 distinguished from the more slender olive-green female catkins. 

 The two kinds are represented on the accompanying plate, the 

 female catkins below, the male above and to the right. The 

 catkins unfold from large lateral buds standing in the axils 

 of leaves which fell off in the preceding autumn. During the 

 winter they were enclosed and protected by hard brown bud- 

 scales. 



The catkin is a specially modified shoot bearing numerous 

 flowers, an inflorescence. It consists of a main stem bearing a 

 few scale-leaves at the base, but in this particular species no foliage- 

 leaves. In the upper part the stem of the catkin bears numerous 

 spirally arranged bracts, in the axil of each of which a single flower 

 stands. The general construction is the same in the male and 

 female catkins. The lower surface and margins of the bracts are 

 clothed with long silky white hairs. These hairs increase the protec- 

 tion afforded by the bud-scales and render the young catkins as 

 they burst from the bud white and silky. When the catkins have 

 reached their full size the bracts are separated slightly by the 

 growth of the stem,and the flowers project from between the bracts. 



