40 BOTANY FOR BEGINNERS. | Ch. VII. 



and rose are woody plants, the lily and pink are herbaceous. 

 Woody plants are divided into trees which have large stems 

 called trunks and grow to a great height, and shrubs whose 

 stems are smaller and which never grow very high. 



145. The use of the stem is to support the branches, leaves, 

 and flowers, and to convey to them, by means of certain tubes, 

 such substances as the root absorbs from the earth. The stem 

 also conveys back to the root, by means of another set of tubes, 

 certain juices which have passed through changes in the leaves 

 If you water a plant with coloured liquid, the stem will in time 

 show that it has ascended into it. 



Fig. 19. 



146. The caulis* or proper stem, is seen iij 

 forest trees, in shrubs, and in most annual 

 plants. The caulis is either simple, as in the 

 white lily ; or branching, as in the geranium ; 

 the branching, is the more common form. You 

 have here, Fig. 19, the representation of a cau- 

 liSj or proper stem, (a) , a peduncle^ or flovvei 

 stalk, (b) ; and a petiole, or leaf stalk, (c). 

 Plants with the real stem, or caulis, are called 

 cauline plants. 



147. Geologists, by examining rocks, and 

 the petrifactions they contain, have found that 

 cauline plants were not created until after such 

 as have culms or stipes. 



* From the Greek kaulos, a stem. 



145. What is the use of the stem 7 

 14G. Describe the caulis or proper stem. 



147. What have geologists discovered with respect to the order of 

 reation of plants? 



