446 PHARMACEUTICAL BOTANY 
branches give rise to other branches which agree with the lateral 
branches in ending in terminal buds. Another kind of branch, 
however, is found which is always shorter than the former 
branches. This type of branch is called a ‘spur shoot” and arises 
from the former branches. The spur shoots bear the needles or 
See ace ewe ; oa 
Fic, 334.—Transverse section of the needle (leaf) of the white pine. Highly 
magnified. ¢p, epidermis; s, stomata; m, infolded parenchyma cells of mesophyll; 
c, cuticle; r, oil reservoir; f, colorless central parenchyma corresponding to the pith 
of the stem; 7, endodermis; x, xylem and fh, phloem of collateral vascular bundles. 
The xylem is composed of tracheids with bordered pores. The leaf shows xero- 
phytic-centric structure. 
foliage leaves which are light-green, when young, and bluish-green, 
soft, flexible, 21¢ to 5 inches long, when mature. The “needles” 
occur in tufts (fascicles) of five, are triangular in cross-section, 
have finely serrate (saw-toothed) edges and are surrounded at the 
base by a deciduous sheath. These foliage leaves persist until 
the end of their second year, when they are shed with the spur 
shoot which bears them. 
