182 IOWA ACADEMY OF SCIENCES. 



and sawed into lumber. In the line of rail fences the 

 white oak had no competitor for durability. Rails are now 

 in use that have resisted the elements for forty years, 

 though the average life cannot be stated to be so long, but 

 is probably ten or fifteen years shorter. On the building 

 of the railways large quantities of white oak timber were 

 used for piling, bridge material, or ties; many of the ties 

 being fashioned with a broad-ax driven by human power. 

 The primeval trees are nearly all gone. The second 

 growth consists of numerous individuals and constitutes 

 the major portion of our white oak groves. The older 

 trees range from sixty to one hundred feet in height and 

 have a trunk diameter of from three to five feet. The 

 young grove trees are from thirty to sixty feet in height, 

 and are from four to ten inches in diameter. The former 

 are usually much-branched, the branches rather large, 

 while the latter are slender and with few or many small, 

 slender branches. The second growtli material gives excel- 

 lent fuel, posts, small piling, etc. 



Our specimens are from Johnson, Van Buren, Appanoose, 

 and Decatur counties. We have observed the species in 

 Winneshiek, Allamakee, Clayton, Jefferson, Wapello, 

 Ringgold, and Union counties. The State University has 

 specimens from Delaw^are, Louisa, Lee, Dallas, Webster, 

 and Pottawattamie counties. Professor Bessey reports the 

 species from Stor> and Des Moines counties; Professor 

 Fink, from Fayette county; Professor Pammel, from Boone 

 and Hardin counties; Mr. Reppert, from Muscatine county; 

 Messrs. Nagel and Haupt, from Scott county; Professor 

 Macbride, from Dubuque and Humboldt counties; Mr. 

 Gow, from Adair county; and Mr. Mills, by letter, from 

 Henry county. 



White, Geol. Sur. of Iowa, Vol. 1, p. 138; Bessey, Contr. 

 to the Flora of Iowa, p. 119; Arthur, Contr. to the Flora of 

 Iowa, p. 29; Hitchcock, Trans. St. Louis Acad, of Science, 

 Vol. 5, p. 517; Nagel and Haupt, Proc. Davenport Acad, of 

 Nat. Sciences, Vol. 1, p. 163; Fink, Proc. Iowa Acad, of 

 Sciences, Vol. 4, p. 101; Fitzpatrick, Proc. Iowa Acad, 

 of Sciences, Vol. 5, p. 127 and p. 163; Vol. 6, p. 196; Iowa 



