212 CORYLACE^:. [CLASS 



Corylacae, together with Salicaceae and Betulaceae, are 

 grouped together by some botanists in a single Family, 

 called Amentaceas, on account of their characteristic 

 form of inflorescence, especially of the staminats flowers, 



FIG. 155. Transverse section of 2-celled ovary of Hazel. 



which are arranged in catkins or aments, that is, in spikes 

 which fall away when the flowers are withered or the fruit 

 has ripened. 



OBSERVE the limb of the perianth of the female flower, 

 usually reduced to very minute teeth, surrounding the 

 base of the style : in some species, as the Hazel, it is 

 almost obsolete. Note, also, the usual abortion in the 

 Order of all the cells of the ovary excepting one, so that 

 the fruit is I -celled, and contains but a single seed, 

 as the Acorn of the Oak, Chestnuts, Hazel-nuts, and 

 Beech-nuts. 



Compare the cupule (involucre) of Oak (Quercus), con- 

 sisting of numerous minute consolidated bracts, contain- 

 ing a single fruit ; Beech (Fagus\ separating into 4 

 valves, and containing 2 fruits ; Chestnut (Castanea), 

 spinose, with 3 or more fruits ; Hazel (Corylus), con- 

 sisting of about 2 leafy accrescent bracts, which overtop 

 the single nut ; and Hornbeam (Carpinus), a 3-lobed 

 bract, subtending a single nut. Compare, also, the fruit 

 of Chestnut with the seed of Horse Chestnut (JEsculus, 

 page 141). 



The Family of Corylaceae is of high importance from 

 the valuable timber-trees which it includes. Foremost 

 amongst them is the Oak (Quercus Robur), the wood of 

 which is more tenacious, elastic, and durable than that 

 of any other indigenous tree. Its bark abounds in 

 astringent principles, which render it valuable for tanning 

 purposes, the tannin of the bark uniting with the gelatine 

 of hides to constitute leather. The acorn-cups (cupules) 



