ASEXUAL REPRODUCTION 71 



169. It is no t in all cases necessary that a seed should be formed 

 in order that a new plant may be developed. Many peren- 

 nials also multiply by a process called budding, which consists 

 essentially of the development from some part of the parent 

 stock of a shoot which ultimately becomes an independent 

 plant. The shoot may spring from the roots, from underground 

 stems, from runners or branches where they touch the sub- 

 stratum or even from leaves. Some species belonging to the 

 group of seed-bearing plants have adopted this method of repro- 

 duction almost to the exclusion of the formation of seeds. 



Classes of Plants 



170. All the so-called flowering plants have one character- 

 istic in common, which is the formation of a reproductive body, 

 the seed, developed from the ovule after fertilization, and con- 

 sisting essentially of an embryo enclosed in a protective seed 

 coat. This group of plants is called Spermatophytes and con- 

 sists of two divisions, the Angiosperms and the Gymnosperms. 



171. The Angiosperms are those seed-bearing plants in which 

 the ovules are enclosed in the cavity of an ovary. Of these 

 there are two classes, the Monocotyledons and the Dicotyle- 

 dons. The difference between these two classes is shown 

 in the following table: 



Angiosperms 



DICOTYLEDONS MONOCOTYLEDONS 



1. Two seed leaves. i. One seed leaf . 



2. Leaves netted veined and 2. Leaves parallel veined with 

 with broken margin. ^margin entire. 



3. Parts of flowers in 45 or 55. 3. Parts of flowers in 35. 



4. Vascular bundles of the 4. Vascular bundles of the stem 

 stem in a single circle form- scattered and no distinction of 

 ing two concentric cylin- wood and bark. 



ders of wood and bark. 

 Either of the characters, 2, 3, or 4, may in some cases fail to apply. 



