STEMS 23 



branches of the primary stem, there is built up a shoot sys- 

 tem, with its leaves and flowers. 



Buds. — A bud is an undeveloped stem; it is simply a young 

 shoot. In an ordinary shoot, an apple or peach twig'^for 

 example, the internodes are considerably elongated. In 

 rapidly growing water sprouts, internodes may be several 

 inches in length. A bud is a very short, young shoot in 

 which the internodes 'are few or are exceedingly short. 

 That a bud is a young, individual shoot in itself is shown 

 by the fact that buds may be removed from a branch 

 and applied to the surface of the growing tissue (cambium) 

 of another branch (stock) and successfully grown there. In 

 fact, bud grafting is a common horticultural practice. The 

 tip of the bud is usually protected by a series of overlapping 

 scales (bud scales), which are in reality modified leaves. 

 Naked buds are not protected by scales; they are found on 

 woody plants of the moist tropics, and are the only sort on 

 herbaceous plants the world over. 



Classification of Buds.^ — Buds may be classified as to 

 development into: (a) leaf, (b) flower, and (c) mixed buds. 

 If we open up a leaf bud, we find a very much shortened axis 

 or stem bearing a number of small leaves. As the leaf bud 

 is a young shoot, it may as properly be called a branch bud. 

 That is, it elongates into a branch which bears leaves. The 

 new shoot, just as the old one from which it came, ends in a 

 bud, and in the leaf axils other buds arise. If we open up a 

 flower bud, we find one or more young flowers. In plums, 

 for example, the number of flowers in a bud varies from one 

 to five, two and three being the most common numbers 

 (Fig. 166). Mixed buds contain both flowers and leaves. 

 The terminal buds at the ends of the short "spurs" in the 

 apple are mixed buds (Fig. 153). 



It is not always possible to distinguish leaf from flower 



