40 



FOUNDATIONS OF BOTANY 



at first in the ground, it develops a slender, leafless stem, 

 which, leaning this way and that, no sooner comes into 



ABC 



FIG. 16. Dodder, growing upon a Golden-Rod Stem. 



s, seedling dodder plants, growing in earth ; h, stem of host ; r, haustoria or 

 parasitic roots of dodder ; Z, scale-like leaves. A, magnified section of a por- 

 tion of willow stem, showing penetration of haustoria. 



permanent contact with a congenial host than it produces 

 haustoria at many points, gives up further growth in its 



