THE AMENTACE^E 



211 



bees and moths. The Poplars are of the Willow Order. 



They include the Lombardy Poplar (Populus pyrami- 



dalis), the Black Poplar (P. nigra), the White Poplar 



(P. alba), and the Aspen (P. tremula). Both Poplars 



and Willows favour temperate and cold latitudes. The 



Oaks, as well as the Beeches, belong to the Cupuliferce, 



in which the sexes occur on the same plant, but not in 



the same flower. In this 



Order are the Common 



Oak (Quercus Robur), the 



Cork Oak (Q. Suber), and 



the Common Beech (Fagus 



sylvatica), the last being 



a familiar forest tree in 



Britain. Another species 



of Beech, Fagus ferru- 



ginea, is as familiar in 



North America as F. syl- 



vatica is in our own woods. 



The Cupuliferse favour 



temperate regions. Cas- 



tanea vesca, the Edible 



Chestnut, a native of the 



Mediterranean region, is 



of the same Order. It has been introduced into Britain. 



In the Birch Order (Betulacece) the sexes appear on the 



same plant. The Order includes the Common Birch 



(Betula alba), the Hazel (Corylus avellana, Fig. 67). the 



Filbert (Corylus tubulosa), which grows in Italy, the 



Hornbeam Carpinus betulus), and the Alder (Alnus 



glutinosa, Fig. 68). The Betulaceae favour Northern 



regions. Willows and Birches are among the most 



FIG. 68. ALDER. 



Branch with male (below) and fe- 

 male catkins ; 2, female flower ; 

 3, male flower. 



