HORNBEAM, HAZEL, BIRCH AND ALDER 97 



The birches constitute the genus Betula, which was the classical 

 name of the European tree. It is the largest genus and gives its 

 name to the family. There are about 30 existing birches recognized 

 by botanists and over four times as many extinct species. They 

 range in size from tiny shrubs under the Arctic Circle, for they 

 extend as far north as any tree genus, to trees 125 feet tall in the 

 case of our northwestern birch {Betula occidentalis) , and some, like 

 our American white birch {Betula populifolia) may be in the far 

 north or on mountains only 2 or 3 feet tall as compared w^ith a 

 height of 40 feet in more favorable situations. Most of the birches 

 are relatively short lived and slender trees, of slow growth, but 

 hardy and freely seeded by the wind, with round slender, often 

 drooping branches, serrate toothed deciduous leaves of a bright 

 green color, with the pollen and seed producing catkins in separate 

 clusters but borne on the same tree, and producing tiny winged 

 fruits. The bark is one of their characteristic features, being in 

 thin layers and readily peeled off, and quite indestructible. 



The accompanying map will explain their distribution much more 

 grapliically than many words. The dwarf Arctic birches of the 

 Pleistocene and recent barren grounds or tundra reach to within 

 ten degrees of the North Pole in western Spitzbergen, and almost 

 as far on the coasts of Greenland. The white birches extend north- 

 ward beyond the Arctic Circle in Scandinavia, Siberia, Alaska and 

 the valley of the Mackenzie, and reach their southern limits in 

 Spain, Asia Minor, Japan and California. The remaining birches 

 occupy large detached areas, the smallest being that of the Caucasus 

 and Armenia. In Asia these forms cover a large area extending 

 from eastern Siberia southwestward to the Vale of Kashmir; in 

 North America they extend from the St. Lawrence valley westward 

 to Minnesota and southward to eastern Texas and Florida. 



Their twigs are still used extensively in the manufacture of 

 brooms just as in ancient Rome the fasces of the Hctors with which 

 they cleared the way for the magistrates, were made of birch 

 rods. Their use among pedagogues was so general in northern 

 Europe and New England that birch is still literally or more often 

 metaphorically the instrument of school room discipline. In 



