APETAL.^ 259 



made from the branches. The knotted roots are used 

 for veneer work. Artists' charcoal is obtained by 

 burning the wood. 



CoRYLUS AvELLANA. — III the illustration {Fig. 72) 

 the occurrence of the Hazel as part of the scrub in an oak- 

 wood is shown, the plant growing socially. The general 

 mode of branching and size of the plant is also shown. 



72. The Willow Group. 



There are about 180 species in the Order Salicacese, 

 and four genera. Amongst British types we have the 

 Poplars with broad leaves, drooping catkins and 

 fringed scales, and the Willows, with narrow leaves, 

 erect catkins, and entire scales. 



They are found in the northern and Arctic regions, 

 but some are Tropical or Subtropical. Arctic types 

 are found in the plant beds of Glacial and earlier age. 



These plants have invariably the tree or shrub 

 habit. The leaves are alternate, simple, deciduous, 

 and the stipules are very characteristic and variable. 

 The Salicacea^ reproduce freely by suckers. 



The plant is dioecious, rarely monoecious. The 

 flowers are devoid of a perianth, and they are in 

 catkins or spikes. The catkins develop in autumn 

 and exist as buds through the winter. There is an 

 annular, pitcher-shaped, or glandular disc. The 

 male flowers are made up of two, three, or five to 

 thirty stamens in the axils of the bract, inserted 

 below the disc. The anther-stalks are free or united 

 below. The anthers, which are basifixed, open in- 



