PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



81 



flowed or very wet for the greater part of the year, and in snch places 

 is found along with the " swell-butt" ashes (^rcfj^tmts amencana ) and 

 other swamp trees. In general apjjearance it very closely resembles 

 the Swamp White Oak [Q. bicolor), branching, like that species, com- 

 paratively near the ground, the lower branches drooping so. as to often 

 touch the ground at their extremities. It is a smaller tree, however, 

 no specimens exceeding 80 feet high and 2^ in diameter having been 

 noticed, though, like other species, it may occasionally much exceed its 

 usual size. 



68. (227.) Quercus macrocarpa. Bur Oak. 



Very common in rich bottom lands. Much the largest, thongh not 

 the tallest of all our oaks, being frequently 5 to 6, sometimes 7, feet 



more. Dr. Schneck gives the maximum dimensious of the Bur Oak as 

 follows: Circumference, 22; clear trunk, 72; total height, 165. Trees 

 of this size are exceedingly rare, however, if not wholly exceptional. 

 The largest that I have measured was 124 feet long to where the top 

 branches had been broken oft", the trunk 63 feet in the clear and 21 feet 

 in circumference, the measurements, in the same order, of the next 

 largest being 162, 30, and 20 feet. A standing tree more than 5 feet in 

 diameter (16 feet circumference) had an ambitus of 130 feet in one direc- 

 tion and 134 feet the opposite way. 



Following are the measurements that I have taken of this tree, in- 

 cluding several by Mr. Thos. J. Johnston and Dr. Schneck: 



Remarks. — e, trunk perfectly solid throughout; r/, "trunk apparently 

 sound"; h, trunk sound. 



60, ( .) Quercus michauxi f 



To this species I refer provisionally an oak which is not a common 

 species in the vicinity of Mount Carmel (the only place I have seen it), 

 but which grows sparingly in rich alluvial soils. So far as I have ob- 

 served, it is rather a small species, resembling in general appearance the 

 (}. muhlenhergi more than any other of our oaks, but having very difierent 

 fruit and foliage. The leaves, 3.25 to 7.00 inches long and 1.50 to 3.50 

 Proc. Nat. Mus 82 6 Jtme IS, 1882. 



