THE STUDY OF TREES IN WINTER 



vary in showing an upright, drooping, or hori- 

 zontal habit of growth, as we see them in the 

 Lombardy poplar, weeping willow and tupelo, 

 and within these divisions there are other con- 

 trasts of rigidity and flexibility, with differences 

 of color and texture as well. 



Apart from the general shape of the tree, the 

 bark on the trunk and branches is a constant 

 help in identification. It is hard and smooth 

 on some trees, like that of the hornbeam and 

 beech, fissured into ridges like the sugar maple 

 on others, it sometimes flakes off in rough plates 

 like those of the shagbark hickory, and again in 

 thin, brittle strips like those of the hop horn- 

 beam, the bark peels off laterally as in the canoe 

 birch, and occasionally becomes ridged and 

 corky as we find it on the branches of the 

 liquidamber and cork elm. Very often the 

 color of the bark is distinctive as is that of 

 the green stems of the sassafras and moose- 

 wood maple and the white, brown, pink, and 

 yellow trunks of different birches. The taste 

 and odor of the bark are also characteristic of 

 certain species, as, for instance, the unpleasant, 

 bitter taste of the black cherry, the mucilagi- 

 nous taste of the slippery elm, and the aromatic 

 fragrance of the stems of the mockernut hick- 

 ory. The little dots on young bark are called 



7 



