50 



ELEMENTS OP BOTANY. 



form the work of leaves. The familiar greenhouse climber, 

 wrongly known as smilax (properly called Myrsiphyllum), 

 bears a profusion of what appear to be delicate green leaves, 

 Fig. 39. Close study, however, shows that these are really 

 short, flattened branches, and each of them springs from the 

 axil of a true leaf, I, in the form of a minute scale. Some- 



FiG. 38. —A Melon-Cactus. 



times, as shown at /, a flower and a 

 leaf-like branch spring from the axil of 

 tHe same scale. 



Branches which, like those of the 

 Myrsiphyllum, so closely resemble 

 leaves as to be almost indistinguish- 

 able from them are called cladophylls. 

 74. Modifiability of the Stem. — The stem may, as in the 

 tallest trees, in the great lianas of South American forests, 

 seen in the frontispiece, or the rattan of Indian jungles, reach 

 a length of many hundred feet, or it may in such "stemless" 



Fro. 37. — Longitudinal 

 Section of an Onion Leaf. 

 2, thicliened base of leaf, 

 forming a bulb-scale ; s, 

 tbin sheatb of leaf ; I, i, 

 blade of the leaf; A, 

 bollow interior of blade. 



