46 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 toa 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. 
VAAL 
146. The cawlis,* or proper stem, is seen in 
Z} 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 ; 
ne } (\ #7 the branching, is the more common form. You 
WiK' WA have here, Fig. 19, the representation of a cau- 
pyle, or proper stem, (a), a peduncle, or flower 
yo Gstalk, (0); and a pee 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? 
146. Describe the caulis or proper stem. 
147. What have geologists discovered with respect to the order of 
ereation of plants? 
