DICOTYLEDONS CUPULIFEBJE DIAGRAM 16 199 



The female flower is often single. The fruit is variable, but 

 consists in many cases of a seed which seems to be contained in 

 a small cup, or cupula, from which the name of the family is derived 

 The cupuliferse yield valuable timber and bark for many indus- 

 trial purposes. The bark of these trees is almost always very 

 bitter. 



The acorn of the oak is the typical example of a fruit contained in 

 a cup. It is well known in what esteem the wood of the oak is held 

 by builders and joiners, for its durability and beauty. The bark is 

 not less useful. When young oaks are cut down, it is carefully 

 removed, and is used in tanning hides, to convert them into leather. 

 The tan after being used, is sometimes spread in the streets in 

 front of houses where a person is dangerously ill, to deaden the 

 sound of passing vehicles. 



Cork is the bark of another kind of oak, which grows in North 

 Africa. When the tree is fully grown, an incision is made at the 

 top and bottom of the trunk, and the bark is removed. It is 

 allowed to dry, and then cut into corks. 



It is 011 the oak that the gall-nuts are produced in some coun- 

 tries by the attacks of the cynips, which are used in the manufac- 

 ture of ink. (See p. 144.) 



The hazel, or nut-tree has a fruit in a cup like the oak, but this 

 covers it entirely. The branches of the hazel are straight and 

 flexible, and are used' for many purposes. 



The poplars and willows generally prefer a damp situation. 

 Their wood is light and of little value, but is used for purposes 

 where lightness without great durability is required ; for making 

 cricket-bats, for instance. Their fruit differs from that of the oak 

 and hazel, and is a capsule which contains seeds furnished with a 

 kind of down : and they are sometimes carried by the wind to a 

 very great distance, when the capsule opens. The young shoots 

 of the willow are extremely strong and flexible ; they are called 

 osiers, and are employed for all kinds of basket-work. 



The Urcli may be immediately recognised in woods by the 

 conspicuous whiteness of its trunk, and by its foliage, which is 



