84 



ACADEMIC BOTANY. 



LESSON XYI. 



BUD AND LEAP. 



173-175. Buds. 176. Gems. 177. Grafting. 178. Bud-Scales. 

 179. Vernation, Praefoliation. 180. Vernation of leaves as regards one 

 another. 181. Leaf-arrangement. 182. Spiral arrangement. 183. 

 Leaf; an organ of digestion. 184. Blade. 185. Transformations. 

 186. Leaf uses. 187. Petiole. 188. Stipule. 



173. 



Buds are of three kinds : Leaf-Bud ; Flower-Bud ; 

 Mixed Bud with both leaves and flowers. 



174. The Leaf-Bud is the beginning of a stem or 

 branch. A point in the centre, around which the 

 leaves are grouped, is the Growth-point (L. Punctum 

 vegetationis). The part to which the leaves are 

 attached is the Pulvinus, another L. word for cushion. 

 In habit, the bud is Naked when without scales, as in 

 the Cinna- 



.A . 



Fio. 107. — Black 



mon (which 

 is tropi- 

 cal, n e e d- 

 ing no pro- 

 tection from 

 cold) ; Scaly 

 when cov- 

 ered by 

 scales, as in 

 the Honey- 



Honeyenckle (Lomt- suckle CFig. prepared to receive it 

 Cera niffi-d): A, axil- ^^_. \ » sertion. 



Fla. 108. — a, bud prepared for insertion ; 5, stem 

 " c, bud and stem after in- 



lary, andX, terminal 

 buds. 



107) 



175. Buds are Axillary and Terminal (Fig. 

 107), as we know ; they are Accessory when two or more 

 are near the axillary bud ; Adventitious when they appear 

 at random on the stem ; Latent when they lie dormant, 

 awaiting an opportunity to put forth. 



176. Gems are solid fleshy buds, which appear in the leaf-axils 

 (Lily) or in the flower itself (Onion). They never grow into branches ; 

 they ripen and fall, imitating seeds ; then take root and form new 

 plants. 



177. Grafting. — Each leaf-bud is the germ of a perfect plant. Gar- 

 deners take a hud from one plant (Pig. 108) and insert it in the stem 

 of another of the same genus. Scions, or cuttings, are treated in the 

 same way. The flrst process is Grafting by Bud ; the second, by Scion. 



