A MANUAL OF BOTANY 



19 



2. Exercises on Various Twigs from Forest and 

 City Trees 



Bud arrangement. Twigs show four possible bud arrange- 

 ments. (1) One bud at each node, each successive bud on 

 the opposite side of the twig from the preceding. True 

 alternate. (2) One bud at each node, with other arrange- 

 ment than in (1). (See the subject Phyllotaxy, in reference 

 books.) Scattered alternate. This is the most common ar- 

 rangement. (3) Two buds at each node. Opposite. (4) Three 

 or more buds at each node. Whorled. 



The bud arrangement is very characteristic of certain 

 trees and tree families, and should be carefully observed. 



Twigs to be drawn. Various twigs ought to be drawn care- 

 fully and brief characteristics written to familiarize the 

 pupil with our common trees. Among those easily obtained 

 are elms, maples, basswood, oaks, ash, cherries, pojylars, cotton- 

 wood, loillows, catalpa, box elder, besides many others of 

 rarer occurrence. The characteristics aside from those 

 shown by the drawing are color, smoothness, odor, of both 

 bark and buds. 



Make a table of all the twigs studied, as follows : — 



