436 NEW ENGLAND TREES IN WINTER. 



BUR OAK 



Mossy-cup or Over-cup Oak. 

 Quercus macrocarpa Michx. 



HABIT Although one of our largest Oaks in the central states, in 

 New England of medium size only 40-60 ft. in height with a trunk 

 diameter of 1-3 ft.; in the open forming a broad, round top with thick 

 spreading limbs and numerous often drooping branchlets. 



BARK Flaky, resembling that of White Oak but rather darker and 

 with ridges rather firmer. 



TWIGS Stout, yellowish-brown, smooth or downy, twigs on some 

 trees after the first year developing corky ridges. LENTICELS minute, 

 pale, raised dots, inconspicuous. LEAVES which sometimes persist, 

 obovate-oblong, divided by deep indentations into 5-7 rounded lobes, the 

 terminal lobe the largest. PITH 5-pointed, star-shaped. 



BUDS Conical to broadly ovate, sharp-pointed or blunt, 3-5 mm. 

 long, reddish-brown, covered with pale wool; lateral buds more or 

 less strongly appressed and flattened against the twig. Stipules often 

 persisting at tips of twigs, long, downy thread-like. BUD-SCALES 

 relatively few to a bud. 



FRUIT Maturing in autumn of first year, very variable, sessile or 

 stalked, generally single. NUT ovate to oval, 2-5 cm. long, apex 

 rounded or depressed, covered with pale down. CUP thick hemis- 

 pherical to top-shaped enclosing from % to the entire nut; scales of 

 cup, pale, woolly, thickened at base with pointed tips, tips of upper 

 scales prolonged into a more or less distinct fringe. 



COMPARISONS The Bur Oak is sharply distinguished from our 

 other Oaks by a number of well-marked characters such as the presence 

 of corky ridges on the young branchlets, the copious fringe to the 

 large acorn, the appressed and downy buds. These characters however 

 are not always present in a given specimen; thus the corky ridges 

 may fail to appear throughout an entire tree; the acorns may be 

 reduced in size and in the distinctness of the fringe; and the lateral 

 buds may be more or less divergent. 



DISTRIBUTION Low rich bottom lands. Nova Scotia to Manitoba; 

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

 Kansas, Indian Territory and Texas. 



IN NEW ENGLAND Maine known only in the valleys of the middle 

 Penobscot and the Kennebec; Vermont lowlands, about Lake Cham- 

 plain, especially in Addison County, not common; Massachusetts valley 

 of the Ware river, Stockbridge and towns south along the Housatonic 

 river; Rhode Island no station reported. 



IN CONNECTICUT Rich bottom lands or swampy places; rare or 

 local and confined to the northwestern part of the state; reported 

 from Canaan and Salisbury. 



WOOD Similar to that of White Oak from which it is not generally 

 distinguished commercially, although superior in strength. 



