

TYPES AND KINDS OF STEMS 53 



86. Leaf-like stems or phylloclades. In these the leaves 

 are reduced to mere bracts, and the stem or branches of it are 

 broadened and flattened so that they resemble leaves. The 

 gardener's "smilax" (Myrsiphyllum), so commonly grown in 

 greenhouses, is a good example. The main stem is slender and 

 cylindrical, but there are numerous branches which are leaf -like. 

 They are known to be branches because they arise in the axils 

 of small scale-like leaves. The asparagus is also an example of a 

 plant in which the stem has taken on the function of leaves, 

 while the latter are rudimentary. 



BUDS OR BUD SHOOTS. 



87. Buds are special types of shoots or branches containing 

 the delicate growing point of the stem. This growing point is 

 usually protected by closely overlapping scales, or hairs, or in 

 some cases it lies in a depression. Buds exist in a resting con- 

 dition through the winter in some climates, or through dry 

 periods in climates where this is the resting period for vegeta- 

 tion. Distinct buds are also usually present at the end of the 

 growing shoot or branch throughout the growing season. The 

 delicate growing point organizes the young leaves which arise 

 near its apex, and the stem tissues which are left behind. The 

 growing point in these buds is protected by the overlapping young 

 leaves, sometimes provided with numerous hairs, and sometimes 

 in addition by a waxy or resinous or gummy substance. As to 

 their means for protection buds are of two kinds, covered and naked. 

 The covered buds have a coating of imbricated or overlapping 

 scales, while buds protected by cork or hairs are said to be naked. 



88. As to their position buds are axillary when they arise 

 as usual in the axil of a leaf; terminal when they are formed at 

 the apex of a shoot or branch; accessory when they arise by the 

 side of or above the one in the axil of a leaf; adventitious when 

 they arise at other points on the stem than in the axils of the 

 leaves or apex of shoots. Adventitious buds also occur on the 

 roots and leaves of some plants. 



89. Protection of buds. Since in our climate the trees and 



