376 



BRITISH FLOWERING PLANTS 



wings, each with its fruit shown in Fig. 297, is homologous 

 with a single cone-scale with its three-winged fruits in 

 Birch. The bracteoles a', h' are undeveloped in Birch. 

 The leaves are pubescent below, on the nerves. The 

 stem is somewhat flattened, and has a considerable 



Fig. 297. 



Fig. 298. 



Fig. 297. — Pair of fruits of Hornbeam, a, b, a\ b', bracteoles forming tlie wing ; 

 /, fruit. Somewbat enlarged. 



Fio. 298. — Diagram of a pair of female flowers of Hornbeam, yl, position of 

 axis of catkin ; B, bract subtending the pair of flowers ; a, b, a, b', bracteoles 

 enveloping each floiyer ; p, rudimentary perianth ; /, pistil of two carpels. 



tendency to form buttresses. Bentham describes it as 

 a small tree, but it often attains a considerable size. It 

 is the most characteristic tree in Epping Forest, where, 

 however, owing to exercise of ancient lopping rights, 

 the individuals are generally much distorted. 



CoRYLUS (Hazel) 



0. Avellana.- — In this species some individuals are 

 protandrous, and others protogynous. These, therefore, 

 would naturally fertilise one anether. The same arrange- 

 ment also occurs in the Walnut (Juglans). The floral 

 arrangement is the same as in Hornbeam (see Fig. 298), 

 but the bracts a, a', b', and b, a', b', instead of forming 

 a three -lobed wing, unite to form the characteristic 

 cupule. 



Tn the male flower the half-anthers in each stamen 

 are distinct, giving the appearance of 8 stamens. 



