STEMS 



79 



however, a^ good many cases in which the stem takes on 

 a more strikingly leaf-like form. The common asparagus 



sends up in spring shoots 

 that bear large scales which 

 are really reduced leaves. 

 Later in the season, what 

 seem like thread-like leaves 

 cover the much-branched 

 mature plant, but these 

 green threads 

 are actually mi- 

 nute branches, 



Ke. 47.— Bulb of Hyacinth. which perform 



(Exterior -view and split lengthwise.) ^Jje WOrk of 



leaves (Fig. 50). The familiar greenhouse 

 climber, wrongly known as smilax (properly 

 called Myrsiphyllum), bears a profusion of 

 what appear to be deKcate green leaves 

 (Fig. 51). Close study, however, shows that 

 these are really short, flattened branches, 

 and that each little branch springs from 

 the axil of a true leaf, I, in the form 

 of a minute scale. Sometimes a flower 

 and a leaf-like branch spring from the 

 axil of the same scale. 



' Branches which, like those of Myrsi- 

 phyllum, so closely resemble leaves as to 

 be almost indistinguishable from them are 

 called ciadophylts. 



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

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



sea 



Flo. 48. — Longitu- 

 dinal Se&tiou of 

 an Onion Leaf. 



aca, thickened base 

 of leaf, forming a 

 bulb-scale; s.thin 

 sheath of leaf ; bl, 

 blade of the leaf ; 

 intt hollow inte- 

 rior of blade. 



