THE BUR OAK OR MOSSY-CUP OAK 



NONE of the Oaks are marked by more distinctive characters than the Bur Oak 

 or Mossy-cup Oak. The form of the leaves is unique, there being on each side 

 near the middle a deep, rounded sinus that reaches almost to the midrib, which 

 practically divides the leaf into two rather distinct parts, the apical part commonly having 

 curious squarish lobes and the basal part having more or less triangular lobes. When 

 once this distinctive feature of the tree is fixed in mind there will be no difficulty in recog- 

 nizing the species at a glance. The fruit is also unique, the broad, smooth nut being 

 nearly enclosed by the curious mossy cup which serves to give the tree one of its common 

 names ; and many of the younger branches also show a distinctive character in the corky 

 ridges along their sides. 



The Bur Oak is found as an indigenous tree over a great region extending from 

 New Brunswick and Nova Scotia to Ontario and Manitoba on the north, to Montana, 

 Nebraska, Kansas, and Texas on the west, and to Pennsylvania, Tennessee, and Massa- 

 chusetts on the south. It appears to be a tree of the Great Plains regions of the West 

 and Northwest, being found most abundantly in the rich soil along river valleys. It is a 

 prevailing species in the so-called "Oak openings" of some of the Northwestern States. 

 Near the junction of the Ohio and Mississippi Rivers many of the trees attain an enormous 

 size, reaching a height of more than a hundred and fifty feet and a trunk diameter of six 

 or seven feet ; but in most regions, especially in the Northeast, it is usually a very much 

 smaller tree and sometimes little more than a shrub. The mode of branching of medium- 

 sized trees growing in the open is well shown in the lower picture of the plate. As will 

 be seen, there is a general tendency of the larger branches to grow upward, and the smaller 

 branches tend even more markedly in the same direction. The bark of the trunk is dark 

 gray and is furrowed by vertical ridges. 



The Bur Oak blossoms about the same time as the other Oaks, when its earliest 

 leaves are half grown, and the large acorns develop the same season. In shape and size 

 the fruits vary greatly, but the cup is unmistakable on account of the mossy fringe around 

 its upper surface. This is an interesting tree for ornamental planting, generally quite free 

 from insect or fungus enemies, and like so many of the other Oaks most easily propagated 

 from acorns planted where the trees are to develop. It thrives to best advantage on rich, 

 moist, well-drained soil, in open sunlight. It grows about as rapidly as the White Oak, 

 considerably more slowly than the Red Oak. Its wood is similar to that of the first named 

 specif s. 



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