BIRCH 



233 



^ 



Betula alba, L. Birch (Figs. 119 and 120). Buds 

 short-ovoid, pointed, glabrous, and somewhat appressed, 

 Avith a tendency to be distichous (see p. 188). Twigs 

 greyish brown when the 

 waxy scales are abundant, 

 but varieties are met with 

 in which they are smooth 

 glistening brown in var. 

 pubescens even pubescent 

 as the older twigs generally 

 are except for the lenticels. 

 Dwarf-shoots not common, 

 and must be distinguished 

 from stalked buds, which 

 they resemble. An acces- 

 sory bud sometimes occurs. 

 Bud-scales ciliate, red-brown 

 or flecked with green, pass- 

 ing to smooth rich brown. ^ ^ 

 Leaf-scars very small, more 

 or less elliptical, with 3 mi- 

 nute leaf-traces, on scarcely 

 prominent leaf-bases (Fig. 

 59 v). Buds often oblique 

 to the scar. 



The true terminal bud 

 is usually aborted and a 

 pseudo-terminal axillary bud 

 replaces it, except on the 

 dwarf-shoots which often 

 end in a bud. The bud- 

 scales are stipular, and the ^. , ^ . , ^ , 



^. Fig. 120. Birch, Betula alba, v. 



leaves lay then- plicate sur- ^,errucossa. a long shoot, ?> dwarf- 

 faces one over the other. shoots (Sc). 



