62 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



were 70 or 80 feet high, and some of them 2 feet or more in diameter, 

 thus appearing too large for JE. glabra. Whichever it may be, how- 

 ever, the Buckeye is a very local tree in the Wabash Valley, and I have 

 only seen it in the locality mentioned, where it appears to be confined 

 wholly to a belt of only a few hundred yards width, a few trees only 

 being found on the opposite side of the river. I am unable to ascribe 

 any reason for this restriction of its range, since the same trees, and 

 other vegetation associated with it, occur throughout the bottoms on 

 either side. It is said to be common among the hills of Gibson County, 

 several miles back from the river, and there to attain a height of 100 feet 

 or more, and a diameter of 3 feet. 



8. (47.) Acer dasycarimm. Silver Maple. 



A very abundant tree along the banks of rivers and large streams, 

 attaining an average elevation of 90 to 100 feet, and a diameter of 2 to 3 

 feet. Unlike the Eed Maple {A. ruhrum) the trunk usually divides low 

 down, usually at about 8 to 15 feet from the ground; the three or more 

 secondary trunks, however, extending upward for a considerable dis- 

 tance before branching. 



Of four trees measured, the extremes were: height, 90 and 118 feet; 

 circumference, 12^ to 14 feet; trunk, 20 feet (only one measured). 



Flowers early in April, leafing from March 31 to April 12. 



9. (51.) Acer ruhrum. Eed Maple. 



A very common tree, but much more local than A. dasycarpum. Is 

 almost wholly confined to swamps or A^ery wet bottoms, where it grows 

 tall, straight, and slender. In size it is about equal to A. dasycarpum 

 and A. saccharinum, but is much more slender than either, with a less 

 spreading top. Three specimens measured 70 to 108 feet in height, the 

 average being 95 J feet; lOi to 15 feet in circumference (average 12.83), 

 clear trunk, 49 to 60 feet. Decidedly taller trees occur, however, those 

 measured being prostrate ones, of by no means the largest size. 



Flowers middle of February to Marcb 20, according to the season; 

 leafs out last of March to April 12. — (Schneok.) 



10. (52.) Acer saccharinnm. Sugar Maple. 



A very abundant tree in some localities, rare or wholly wanting in 

 other portions. Occasional "sugar groves" occur where, over a space 

 of several acres, scarcely a single tree of any other species can be found. 



The larger trees of this species average about 100 feet high (the aver- 

 age of the five specimens measured being 108| feet, the extremes 90 and 

 118), and 2^ to 3, occasionally over 4, feet in diameter. The trunk, like 

 that of A. ruhrum, is frequently tall and straight, fonr specimens meas- 

 ured being, respectively, 47, 48, 60, and 70 feet to the first limb. The 

 var. nigrum and the common form appear to be about equally numerous, 



