Issued January 19, 1907. 



United States Department of Agriculture, 



FOREST SERVICE Circular 56. 



GIFFORD PINCHOT, Forester. 



FOREST PLANTING LEAFLET. 



BUR OAK (duercus macrocarpa). 



FORM AND SIZE. 



The bur oak is one of the largest trees found in central North 

 America. It frequently attains a height of from 80 to 90 feet and a 

 diameter of from 3 to 4 feet. Under the most favorable conditions it 

 has reached a height of 170 feet and a diameter of 7 feet. When 

 grown free the crown is large and heavy; in the forest it is usually 

 contracted and covers only the upper part of the tree. 



The distinguishing feature of the bur oak is that from which it gets 

 its name the mossy fringe about the rim of its deep acorn cup. The 

 leaf is large and deeply lobed and resembles that of the white oak. 

 When the twigs are from three to four years old they begin to develop 

 corky wings, which sometimes attain a width of an inch or more. 

 These disappear as the branch grows older, and consequently are seen 

 only on the younger growth. 



RANGE. 



The natural range of the bur oak is from Manitoba to Texas, and 

 eastward to the Atlantic coast. It is commonest and most important 

 in the lowland forests of the Mississippi basin, whjare it is found asso- 

 ciated with white oak, basswood, white ash, cottonwood, black walnut, 

 and several hickories. In the Dakotas and about the Great Lakes it 

 sometimes occurs in pure stands, forming the characteristic " oak 

 openings." East of the Alleghen}' Mountains it is comparatively 

 rare and local, and near the northern and northwestern limits of its 

 range it dwindles to a mere shrub. Bur oak may be planted on good 

 soils almost anywhere east of the ninety-eighth meridian and in 

 favorable situations somewhat farther west. 



SILVICAL QUALITIES. 



The bur oak is best suited to deep, rich, river-bottom soils. It will 

 maintain itself in poorer upland localities, but it is recommended for 

 planting only where the soil is fairly good, moist, and well-drained, 

 and where protracted droughts are infrequent. It is rather intolerant 

 of shade, and will not thrive beneath the crowns of taller trees. 

 16761 No. 5607 M 



