9 6 



CONDENSED TYPE OF STEMS 



plantains, dandelions, etc. Frequently these short stems are 

 associated with an abundance of foods that are stored in roots 

 or other organs. Such plants can quickly send up and mature 

 their flower stalks or leafy stems and thus avoid unfavorable 

 conditions, as drought, competition, with larger vegetation that 

 will appear later, etc. This habit has been made very con- 

 spicuous by cultivation in many plants, as the carrot, turnip, 

 radish, and beet. But in nature the very short, almost flat stems 

 and fleshy roots are also of common occurrence, e. g., the wild 

 carrot, wood betony, dandelion, etc. In many cases the short 

 stem itself is the storage organ and consequently it becomes en- 



FIG. 72. Shortened types of stems: A, corm of jack-in-the-pulpit. At 

 left surface view showing lateral buds, roots and sheathing leaf arising 

 from top of shortened stem. At right sectional view with folded leaf, /, 

 in bud at apex of stem. B, bulb type of shortened stems. At left bulb of 

 onion showing the ensheathing leaves which are swollen at their bases 

 with food, thus forming the bulb. At right, section of a bulb of hyacinth 

 showing the fleshy leaves attached to the very short stem and in the center 

 of the bulb a flower cluster. 



