QUERCUS MACROCARPA, MICHX. 79 



Quercus macrocarpa, Michx. 

 BUR OAK. OVER-CUP OAK. MOSSY-CUP OAK. 



Habitat and Range. Deep, rich soil ; river valleys. 



Nova Scotia to Manitoba, not attaining in this region the size of 

 the white oak, nor covering as large areas. 



Maine, known only in the valleys of the middle Penob- 

 scot (Orono) and the Kennebec (Winslow, Waterville) ; 

 Vermont, lowlands about Lake Champlain, especially in 

 Addison county, not common ; Massachusetts, valley of 

 the Ware river (Worcester county), Stockbridge and towns 

 south along the Housatonic river (Berkshire county) ; Ehode 

 Island, no station reported; Connecticut, probably intro- 

 duced in central and eastern sections, possibly native near 

 the northern border. 



South to Pennsylvania and Tennessee ; west to Montana, Nebraska, 

 Kansas, Indian territory, and Texas. 



Habit. A medium-sized tree, 40-60 feet high, with a trunk 

 diameter of 13 feet ; attaining great size in the Ohio and 

 Mississippi river basins ; trunk erect, branches often changing 

 direction, ascending, save the lowest, which are often nearly 

 horizontal ; branchlets numerous, on the lowest branches often 

 declined or drooping ; head wide-spreading, rounded near the 

 center, very rough in aspect ; distinguished in summer by 

 the luxuriance of the dark-green foliage and in autumn by 

 the size of its acorns. 



Bark. Bark of trunk and branches ash-gray, but darker 

 than that of the white oak, separating on old trees into 

 rather firm, longitudinal ridges ; bark of branches sometimes 

 developed into conspicuous corky, wing-like layers; season's 

 shoots yellowish-brown, minutely hairy, with numerous small, 

 roundish, raised dots. 



Winter Buds and Leaves. Buds brown, ^ to ^ inch long, 

 conical, scattered along the shoots and clustered at the 

 enlarged tips. Leaves simple, alternate, 6-9 inches long, 

 3-4 inches broad, smooth and dark green above, lighter and 



