94 NATURE OF PROSTRATE STEMS 



become separate plants by the decay of the old stem, as in 

 the strawberry, gill-over-the-ground, cinque foil, etc. These 

 new plant- repeal the mode of growth of the parent plant and 



I'n,. <*). House leek Conning buds at the end of short branches or stolons. 



in this way man} prostate stems spread out over the soil, c >tal >- 

 li>hin.u" new plants in wider and wider circles. If you will ob- 

 serve the number of new plants established and the distances 

 traversed by some of these creeping stems each year you will 

 see the reason for the common occurrence "i the large mat- and 

 colonies of plants with prostrate stems. 



47. The Rhizome Type of Stems. — In a third type, the stems 

 have become so modified that thej respond to the various stimuli 

 in quite a different way from the forms noted above. They 

 creep along in the soil and frequentlj resemble roots more than 

 stems. For this reason they are called rootstocks or rhizomes. 

 They are, however, real stems, as i> attested by the numerous 



leaves and often erect branches that spring from their nodes 



een in the fern-, sweel flag, cat tail, grasses, etc. I'lant- of 



this type are well protected againsl drought, cold, and fires, and 



like prostrate steins they are adapted t" establishing new plants 



a- i- apparent in grass} meadow-, colonies of golden-rod ami 

 daisies or reedy hank- of eat tail-, sedges, etc. These stems 

 are al-o well adapted to propagating new plants because they 

 generall} serve ;i- storage organs for food and are therefore 

 often of a flesh) character (Fig. 701. For these reasons it is 

 sometimes ver> difficult to eradicate plants of this type. This 

 rj well illustrated in the quack grass, often a troublesome 

 pe-t in cultivated land. Plowing and hoeing onl) serv< 

 break up the rhizome into numerous parts each of which may 



