314 



a more or less exteusive range. lu the district east of the Eocky Mouut- 

 ains we have about twenty-two species ; west of the Missouri Kiver 

 they become very scarce, gradually disappearing before the base of the 

 mountains is reached. The central chain of the mountains furnishes 

 but one or two species. The western slope of the Sierra JS'evada pre- 

 "feeuts eight or ten species, and Mexico and Central America many more. 



The oak family is, perhaps, on many accounts, the most valuable of 

 forest-trees. Its value depends chiefly upon its quality and abundance 

 as a timber-tree. It would be difficult to supply its place in ship-build- 

 ing and in many of the useful arts, including its extensive employment 

 in the construction of railroads. Almost nothing has yet been done iu 

 this country in the way of planting or cultivating the oaks, but it is 

 desirable that the attention of our jieople should be directed to the im- 

 portance of this subject, and to the kinds most valuable and most easily 

 cultivated. Although it is a tree of slow growth, yet, with our accus- 

 tomed thoughtlessness for the future, we have pressed it into our service 

 without stint or measure, and we are just beginning to wake up to a re- 

 alization of the fact tliat we are ruthlessly destroying the noblest forests 

 in the world without making provision for their reproduction. In order 

 to facilitate the study of this noble genus of trees, and to direct atten- 

 tion to the different kinds, Ave propose to give a short account of their 

 general characteristics and their classification. 



The princijial characters of the genus are as follows : Trees or shrubs 

 with alternate leaves, and with sterile and fertile flowers separate ; the 

 sterile ones ou slender, thread-like, drooping stems ; the fertile ones 

 small and inconspicuous, consisting of a three-celledx)vary, inclosed by a 

 scaly covering, which, when enlarged, becomes a kind of cup to con- 

 tain the fruit or acorn. Although the ovary is at first three-celled, 

 with two ovules in each cell, yet but one of the ovules is fertile, and 

 that one enlarges to fill the whole cavity/ 



All our species of oaks are divided into two sections, distinguished 

 by the time occupied in the full development of the fruit. First, those 

 which mature the fruit in one season, and hence called annual fruited ; 

 and second, those whose fruit is two years iu acquiring maturity, and 

 called biennial fruited. The first section includes the white and chest- 

 nut-oaks and the live oak of the Southern States. Of these the leaves 

 usually have blunt lobes ; and the acorns are sweet or sweetish, and 

 some of them edible. In this section the acorns are produced on the 

 Oleic twigs, i. e., the twigs of the same season's growth, and they are 

 generally more or less stalked. In the second section the leaves are 

 either entire or lobed and bristle-pointed ; the acorns are bitter, and 

 are matured on the twdgs of the last season, and below the new shoots. 

 This section includes the red and black oaks, the Spanish and pin 

 oaks, and the willows-leaved oaks. Although these are called biennial 

 fruited, it is not meant that they produce fruit only once in two years. 

 The yotmg fruit is formed on the new twigs, but it remains in a dormant 

 state until the second year, when it swells and matures. On these 

 trees, therefore, there is usually a crop of young fruit and a crop that 

 is maturing. 



The following sketch will give a comprehensive view of the species 

 east of the Kocky Mountains, with some observations on their range 

 and variations : 



Section' 1. — Annual fkuited oaks. 



Bur-oalcs. — Leaves lobed. 



1. Buroaks — Quercns macrocarpa, Michaux. — This tree has its largest 

 development in the AVestern States, particularly in Illinois, Wisconsin, 



