KINDS OF STEMS 



15 



are often said to be stemless, however, in order to dis- 

 tinguish them from plants which have long or conspicuous 

 stems. These so -called stemless plants die to the ground 

 every year. 



38. Stems are erect when they grow straight up. Figs. 

 1, 2, 3. They are trailing or creeping when they run 

 along on the ground. Fig. 19. They are decumbent 

 when they lop over to the ground. They are ascending 

 when they lie mostly or in part on the ground but stand 

 more or less upright at their ends. They are climbing 

 when they cling to other objects for support. Figs. 12, 20. 



39. Trees in which the main trunk or the "leader" 

 continues to grow from its tip are said to be excurrent in 

 growth. The branches are borne along the sides of the 

 trunk, as in common pines (Fig. 21) and spruces. Excur- 

 rent means running out or running up. 



40. Trees in which the main trunk does not continue 

 are said to be deliquescent. The branches arise from one 



common point or from each other. 

 The stem is lost in the branches. The 

 apple tree (Fig. 18), maple, elm, oak, 

 are familiar examples. Deliquescent 

 means dissolving or melting away. 

 41. Each kind of plant has its 

 own peculiar 

 habit or direc- 

 tion of growth. 

 Spruces always 

 grow to a single 

 stem or trunk, 

 pear trees are 

 always deliques- 

 cent, morning-glories are always climbing, strawberries 

 are always creeping. We do not know why each plant 

 has its own habit ; but the habit is in some way asso- 



19. A trailing plant (Abronia). 



