172 Eleventh Annual Report 



3. QUERCUS. The Oaks. 



(From the Celtic, quer, fine, and cues, tree; in reference to the quality of the trees.) 



The leaves of the Indiana species are deciduous; flowers appear 

 in April or May, staminate flowers in slender pendulous catkins, 

 the pistillate solitary or in clusters in a scaly bud-like cup; fruit an 

 acorn which takes one or two years to mature, ripening in the 

 autumn. The trees that mature their fruit the first year are classed 

 as white oaks and those that mature them the second year are called 

 red, black or bristle-tipped oaks. 



The oaks are the longest lived of our native trees. They are 

 peculiar in the amount of their annual growth, especially the white 

 oaks. An examination of the annual rings of the oak will show 

 that the rate of growth is nearly uniform from youth to old age. 

 The slowest rate of growth will be found for the first five to twenty 

 years. Almost all other trees show large annual rings in early 

 years with a gradual decrease after the tree has fully matured 

 With some trees the maximum growth rate is reached midway 

 between youth and old age. The vitality of the acorn is short 

 and nuts over a year old seldom, if ever, germinate. Nuts that 

 are to be planted should be planted soon after they fall from the 

 tree. 



This is the largest genus of Indiana trees and furnishes some of 

 our most valuable hardwoods. The bark of some species contains 

 a large percentage of tannin, and formerly tan bark was an import- 

 ant article of commerce in the State. On account of their astringent 

 properties, the bark, as well as the galls of some species are used in 

 medicine. 



The heavy fruiting of the oaks was an important item to the 

 pioneer, who was accustomed to feed his swine on the nuts of the 

 forest, which were known as '^mast", of which the acorns formed 

 the greater part. 



Bark gray, more or less scaly; mature leaves never with 

 bristle tips; fruit maturing the first year. 

 *Leaves lyrate or sinuate lobed. 

 Mature leaves pale or glaucous and glabrous beneath. 1 Q. alba. 

 Mature leaves finely pubescent beneath. 

 Terminal scales of the cup not awned. 



Pubescence on leaves beneath brownish; fruit 

 nearly sessile; cup one-third to half as high 



as the ovoid acorn 2 Q. stellata. 



Pubescence on leaves beneath whitish; fruit 

 stalked, cup nearly covering the depressed 

 globosejacorn 3 Q. lyrata. 



