CLASSIFICATION OF ANGIOSPERMS. 511 



b. FAGACE^ OR BEECH FAMILY. This family includes 

 some of our largest forest trees, these being rather characteristic 

 of temperate regions. They are all highly valued for their timber, 

 and yield other valuable products besides. One notable character- 

 istic is that all of the chestnuts and oaks and some of the beeches 



FIG. 283. White oak (Quercus alba): A, characteristic, lobed leaf; B, young branch 

 showing pistillate (p) and staminate (s) flowers; C. hairy bracts of a staminate flower; D, 

 group of hairs from bract; E, stamen; F. pollen grains; G, cluster of pistillate flowers; H, 

 acorn with cupule; I, starch grains from acorn, which vary from 10 to 25 M long; J. trans- 

 verse section of bark showing cork (k). stone cells (st), bast fibers (b), crystal fibers (ca), 

 medullary rays (m), parenchyma (p) ; K, longitudinal section of bark showing end of bast 

 fiber (b) crystal fibers (ca) and parenchyma cells (t) containing tannin. 



contain tannin in the wood, bark, and leaves. The oaks are further 

 notable in being prone to the attack of gall-producing insects 

 (various species of Cynips) whereby the peculiar excrescences 

 known as galls are formed on the leaves and young shoots. Among 

 the oaks which yield galls rich in tannin are the following : Quercus 

 infectoria of the Mediterranean, which yields the official Turkish 



