THE PLANT \\"()RLD UNDER CARE 



SEXERAL P.RYOPIIYLLUM PLANTS MAY BE GROWN FROM OXE LEAF. 



An Interesting Twining Root. 



IIY DR. C.KokCK T. SThVK-XS, XK\V YORK Cri'Y 



Plants such as bear flowers and 

 fruit, grasses, the common field plants, 

 trees and others, are characterized by 

 certain general forms of their three 

 principle parts. These three parts are 

 the stem, the leaves and the root. 

 There is a diversity of form for each 

 of these structures depending largely 

 upon the species of plant. To the fea- 

 tures of only two of these parts is at- 

 tention called here. 



First, if Ave examine the stems of 

 many plants, we soon find that we may, 

 in a pretty general way, divide them 

 into three groups. These groups are 

 the erect stems, such as those of trees, 

 grasses and many familiar plants ; then 

 the weak stems, one group of which 

 lies prone upon the surface of the 

 ground, as for example, do the stems 

 of the creeping- partridge berry (Mitch- 

 cUa rrpciis), or those of the twin flower 

 (Liiniaea borealis) ; or in a sub- 

 group of these prostrate stems a con- 

 siderable part may be covered by the 

 soil as in the case of the gold thread 

 (Copfis tri folia). 



A third group of stems includes 

 those which, although too w-eak to sup- 

 port themselves, prefer to rise above 

 the soil by the aid of more robust 

 stems or other objects. Familiar ex- 

 amples are the stems or vines of the 

 climbing bean, the hop, the pea and the 

 morning glory. 



Here again we find a grouping de- 

 pending on the method of support. For a twixing parsxip. 



