ROOTS AND STEMS. 2 l 



EXERCISE VIII. 

 Stems and their Parts. 



Pull up any herb which has a distinct stem and com- 

 pare the stem with the root. Herbs are plants having stems 

 that die down to the surface of the ground every year. If 

 the root dies as well as the stem, the plant is called an 

 annual ; but if it lives and sends up a flowering stem the 

 second year, and then dies, it is a biennial / while, if the 

 root lives on from year to year and only the stem dies, the 

 plant is perennial. 



Observe the parts growing from the stem. What is at 

 the top ? at the end of each branch ? Do you find the same 

 structures at the tips of the roots ? Name all the differ- 

 ences you can find between the stem and root. Com- 

 pare an herb with Fig. 59, where the stem (/) is repre- 

 sented as giving off leaves (ff) in a regular manner. 

 Look at several branching stems, to find if the branches 

 are put forth regularly. Is there any regularity in the 

 growth of roots ? Observe, in Fig. 59, that the angle 

 made by the leaf with the stem contains a bud, b. What do 

 you find in this angle in living plants ? Botanists call this 

 angle a leaf-axil, and its bud an axillary bud. Buds at the 

 free end of stems and branches are called terminal buds. 



The points on a stem at which leaves are given off are 

 called nodes, and the spaces between the nodes are internodes. 



Point out the nodes, internodes, axillary buds, and ter- 

 minal bud of the main stem (primary stem) of as many 

 plants as you can gather. Point out the same parts upon 

 the secondary stems or branches. 



EXERCISE IX. 

 Buds. 



The time to study winter buds is in early spring. 

 Choose a swollen bud and observe well its outer covering. 



