260 THE SEED PLANTS : FORMS AND LIFE HISTORIES 



FIG. 41. A, young plant of the Field Bindweed (Convolvulus arvensis), 

 showing the thin white underground shoots (rh.) which ramify deeply 

 in the soil and make the plant a troublesome weed. B, hori- 

 zontally growing rhizome of a grass. C, plant of the Chickweed 

 Wintergreen (Trientalis) which has arisen from the tuber (<'). The 

 new tuber (t 1 ) has arisen at the end of the rhizome, rh., rhizomes ; 

 r, adventitious roots ; sc.l., scale leaves ; a.s., aerial shoots. (After 

 Warming.) 



