158 



STEMS 



difficulty at all for rhizomes. They can burrow along 

 among other plants just about as well as where there are 

 no plants. Indeed they seem to be most successful in soil 

 which is already well occupied by other plants. 



On freshly cleared land, or on fields left fallow after a 

 crop, annual plants spring up in great abundance in the 

 first season. This is because the light, wind-blown seeds of 

 the annuals are the first to occupy the new territory, and 

 because their seedlings have an unusual chance to take 

 root. But gradually rhizome plants and other perennials 

 encroach on the annuals, and, if undisturbed, will finally 

 drive them out. 



B. Tubers. — It is the potato which has made tubers 

 famous. If it were not for this celebrated plant, the word 

 tuber would be no more familiar than the word corm. 

 But the potato has proved one of the best friends which 

 man has in the plant world, and every one should know 

 something of its culture. 



Probably you have noticed the eyes on the skin of the 

 potato. The eyes are at the nodes of this swollen, under- 

 ground stem. They 

 are composed of small 

 scale-like leaves and 

 buds. The bud is at 

 the axil of the leaf. 

 (See Figure 54.) 



When potatoes are to 

 be planted, selected 

 tubers are cut into 

 pieces, each piece bearing one or two eyes. These pieces 

 are planted a few inches below the surface of the soil 



Fig. 54. — A potato showing the eyes. These 

 are composed of scale leaves with buds in their 

 axils. One of these buds has begun to sprout. 



