BUDS 33 



may long remain latent, and at length upon a favorable occasion start 

 into growth, so forming branches apparently out of place as they are 

 out of time. The new shoots seen springing directly out of large 

 stems may sometimes originate from such latent buds, which have 

 preserved their life for years. But commonly these arise from 



40. Adventitious Buds. — These are buds which certain shrubs and 

 trees produce anywhere on the surface of the stem, especially where 

 it has been injured. They give rise to the slender twigs which often 

 feather the sides of great branches of our American Elm. They 

 sometimes form on the root, which naturally is destitute of buds ; 

 they are found even upon some leaves ; and they are sure to appear 

 on the trunks and roots of Willows, Poplars, and Chestnuts, when 

 these are wounded or mutilated. 



41. Definite annual growth from winter buds is marked in most 

 of the shoots from strong buds, such as those of the Horse-chestnut 

 and Hickory. Such a bud generally contains, already formed in 

 miniature, all or a great part of the leaves and joints of stem it is to 

 produce, makes its whole growth in length in the course of a few 

 weeks, or sometimes even in a few days, and then forms and ripens 

 its buds for the next year's similar growth. 



42. Indefinite annual growth, on the other hand, is well marked 

 in such trees or shrubs as the Sumac, and in sterile shoots of the Rose, 

 Blackberry, and Raspberry. That is, these shoots are apt to grow all 

 summer long, until stopped by the frosts of autumn or some other 

 cause. Such stems commonly die back from the top in winter, and 

 the growth of the succeeding year takes place mainly from the lower 

 axillary buds. 



43. Forms of trees determined by the development of the buds. — 

 The main stem of Firs and Spruces, unless destroyed by some injury, 

 is carried on in a direct line througliout the whole growth of the tree, 

 by the development year after year of a terminal bud : this forms a 

 single, uninterrupted shaft, — an excurrent trunk, which cannot be 

 confounded with the branches that proceed from it. Of such spiry or 

 spire-shaped trees, the Firs or Spruces are characteristic and familiar 

 examples. 



44. On the other hand, when the terminal bud fails to take the 

 lead regularly, there is no single main stem, but the trunk is soon lost 

 in its branches. Trees so formed commonly have rounded or spread- 

 ing tops. The American Elm is a good illustration of this type, in 

 which the stem is said to be deliquescent. 



Supplementary Work. Ecology of Buds 



The following outline is meant to suggest some lines of individual research 

 that may be followed throughout the year in any place where plants grow. 

 Notes made from nature will not, of course, follow this scheme ; for such a 



OUT. OF EOT. 3 



