PHAXEROGAMIA 



557 



This order was formerly united with the Juglandiflorae and 



Flo. 562. Altiits glutinosa. 1, Flowering branch bearing the small, erect, female catkins and the 

 pendulous, male catkins. 2, A bract-scale with male flowers. 3, Female catkins. U Female 

 flower. ;", Catkin in fruiting condition. 6, Fruit. (1 and the leaf, f nat. aixe ; 2-6, enlarged.) 



Saliciflorae in the Amentiflorae ; they include most of our important 

 forest-trees. 



Family 1. Betulaceae. Male flowers adherent to 

 the bracts ; in catkins. Female flowers in catkin*. 

 Ovary bilocular, with two long stigmas ; a single, 

 pendulous ovule in each loculus. 



MOST IMPORTANT GENERA. Alnus glutinosa, the 

 Alder, is a prominent tree of damp woods, and is also 

 distributed in swamps and by the banks of streams 

 (Fig. 562). The leaves are bluntly obovate. The 

 inflorescences are already evident in the autumn as 

 stalked catkins, the male long and pendulous, the 

 female erect and short. Male flowers P 4, A 4 ; a 

 dichasium of three flowers adherent to each bract 

 (Fig. 563). The female flowers are in pairs, their 

 bracteoles adhering to the bract to form the five-lobed, 

 persistent, woody scale of the cone. Alnus incana 

 is distinguished by its leaves being grey and hairy 

 below. Betula verrucosa (Fig. 564), the Birch, has a white bark and long-stalked, 



FIG. 563. Alnus glutinosa. Dia- 

 grams of Fig. 562, 2 and k. Bract 

 6 ; bracteoles a j3, a' ft', a, /3,. 

 (After EICHLER.) 



