Plants in Relation to Man 499 



state by more than a million dollars. Thus seedlings may 

 have value if properly selected. 



Bud varieties. As there are new varieties possible from the 

 seeds of the plants of this group, so there are new varieties 

 possible from buds on the plants. In fact sports from seeds 

 and buds are the source of many of the improvements that 

 have been made in plant culture. Bud sports may be illus- 

 trated by the navel orange. A single bud on an orange tree 

 grew into a branch bearing oranges without seeds, but con- 

 taining in the blossom end of the fruit a small " navel " orange. 

 The seedless orange branch was propagated by grafting on other 

 trees, and the buds thus produced used in " budding " a large 

 number of orange trees. In a similar way nectarines were 

 produced as a bud variety on a peach tree. There are many 

 cases of such chance variations continued by careful propaga- 

 tion among the cultivated flowering plants, such as the roses, 

 chrysanthemums, carnations, tulips, and geraniums. 



V. PROPAGATION OF PLANTS 



241. Division. Many plants which are not ordinarily 

 grown from seed may be propagated by buds. The method 

 employed in this is known as division. It is the artificial 

 separation from the parent plant of a bud, or a part having 

 several buds, which will develop into a new and complete plant. 

 The general method of budding is applied in several ways, i.e. 

 layering, cutting, budding, and grafting. 



In this work man has been guided by what he has observed 

 in nature. The potato, which is a good example of propagation 

 by buds, produces tubers on the tips of underground branching 

 root stalks. The tubers remain after the death of the parent 

 plant and the next season produce new plants. Men increase 

 the number of plants as well as secure better products by select- 

 ing and cutting the tubers into sections, each of which has two 

 or more buds, and planting the sections. Sweet potatoes, 

 which are enlarged roots and produce shoots, are planted whole 



