PARTIAL SHADE ADVANTAGEOUS. 71 



completed, except on vigorous shoots, in June. In some of the culti- 

 vated plants which were not shaded growth was similarly stopped by 

 the advent of hot weather. In the plants under the slat shades, how- 

 ever, vigorous stems did not wither their tips until their normal 

 grov;^th had run its course, and as new shoots were continually start- 

 ing there was no general stoppage of growth until September, and 

 many of the plants continued to grow throughout that month. 



The shade was not great enough to "draw" the plants; that is, 

 to make their growth spindling through a stretching up for light. 

 It was merely sufficient to prevent excessive heat and destructive 

 transpiration. 



(30) The flowering buds of the blueberry are produced by the transforma- 

 tion OF DORMANT LEAF BUDS IN THE LATTER PART OF THE SEASON. 



The flowers and leaves of the swamp blueberry are produced in 

 the spring from separate buds, and these buds are formed in the 

 preceding year. The two kinds of buds are conspicuously different, 

 as may be seen by the accompanying illustration. (PL X, fig. 1.) 

 The leaf buds occupy the low^er part of the twig. They are small, 

 conical, about 0.08 to 0.12 of an inch (2 to 3 mm.) long, with 2 to 4 

 external scales about equaling each other in length and each ending 

 in a sharp point. The points only of the interior scales, which are 

 of similar length, are visible. When a leaf bud develops in the 

 spring it produces a leafy twig. 



The flowering buds are borne along the upper part of the twig. 

 They are fat, ovoid structures, commonly 0.15 to 0.3 of an inch 

 (3.5 to 7 mm.) long, several times larger than the leaf buds. They 

 show ordinarily 10 to 15 external, broad, overlapping scales. Each 

 flowering bud contains the rudiments of a raceme of usually 7 to 12 

 flowers, the bud of each of these flowers lying in the axil of a bract 

 and bearing two bractlets below the middle of its short pedicel. 

 When a flowering bud develops it produces a raceme of flowers, but 

 no accompanying twig or leaves. 



Leaf buds are always axillary and flowering buds almost always 

 so. The bud at the summit of a twig is in reality situated in the 

 axil of the uppermost leaf, except in the rare cases in which the twig 

 tip does not wither when it stops its growth. In such cases a true ter- 

 minal bud is formed, surrounded by a group of lateral buds in the 

 axils of bracts. So far as observed these buds are always flowering 

 buds and are produced on the ends of vigorous shoots. 



The manner in which the plants lay down their flowering buds, 

 through the transformation of leaf buds, is very interesting, and it 

 may prove to have a bearing of some importance on the method and 

 time of pruning the bushes. The form of the leaf buds has already 

 been described. They appear singly in the axils of the leaves almost 



193 



