IOWA ACADEMY OF SCIENCES. 
171 
Fink, Proc. Iowa Acad, of Sciences, Yol. 4, p. 101; Fitz- 
patrick, Proc. Iowa Acad, of Sciences, Yol. 5, p. 127, and p. 
168; Yol. 6, p. 196; Cameron, Iowa Geol. Sur., Yol. 8, p. 198; 
Macbride, Iowa Geol. Sur., Yol. 4, p. 119; Yol. 7, p. 107; 
Yol. 9, p. 152; Yol. 10, p. 647; Reppert, Iowa Geol. Sur., Yol. 
9, p. 886; Britton and Brown, Ills. Flora, Yol. 1, p. 509. 
B etui a lutea Mx.’f. Arb. Am., 2: 152, PL 5, 1812, 
This species is reported by Barnes, Reppert, and Mille** 
from Scott and Muscatine counties in Proc. Davenport 
Academy of Natural Sciences, Yol. 8, p. 256. They state 
that the species is common along rivers. They mention 
no other birch, and as Mr. Reppert had only shortly before 
reported Betula nigra L. as common along streams in Mus- 
catine county in his article, Forest Trees and Shrubs in 
Muscatine County, published in volume 9 of the Iowa 
Geological Survey, there seems a probable error. Britton 
and Brown give the range of this species as Newfound- 
land to Manitoba, south to North Carolina and Tennessee, 
mainly in the Alleghanies. In all probability Betula nigra 
L. was the species considered and that Betula lutea Mx. f. 
does not occur in Iowa. 
Betula papyrifera Marsh. Arb. Am., 19, 1785. Paper or 
Canoe Birch. A tree, usually thirty to sixty feet high, 
usually one to two feet in diameter, with chalky white 
bark separable into very thin sheets, and brownish twigs; 
leaves ovate, acuminate, unequally doubly serrate, slender 
petioled, base obtuse to subcordate, glabrous and green * 
above, glandular and somewhat pubescent beneath. 
This species is frequent in rich woods, along streams, in 
northeastern Iowa. The wood is light, strong, tough, 
close-grained; mostly used for fuel in Iowa; may be used 
in the manufacture of spools, shoe-lasts, pegs, turnery, 
etc. The tough bark separating easily into thin layers is 
very durable and impervious to water, and has been used 
by the Indians in the manufacture of canoes and tents. 
Our specimens are from Winneshiek county. We have 
observed the species in Allamakee, Clayton, and Dubuque 
counties. The State University herbarium has specimens 
from Delaware county. Professor Fink reports the species 
