CYPKESS AND JUNIPER TREES OF ROCKY MOUNTAIN REGION. 13 



COMMON JUNIPER.' 



Juniperus communis Linnaeus. 



COMMON NAME AND EARLY HISTORY. 



The common or dwarf juniper is the most widely distributed tree 

 inhabiting the northern half of the globe. 2 It was technically named 

 and described hi 1753, probably from specimens obtained from north- 

 ern Europe. Apparently, however, it was previously long known 

 in Europe and in Asia. It is difficult to determine when it was first 

 found in North America. The earliest botanical account of it, how- 

 ever, as a native of this country appeared in about 1803. Juniperus 

 communis has a long botanical history in which various forms have 

 been described under about sixteen different specific and varietal 

 names. Thirteen varieties are now distinguished in cultivation, the 

 best marked one being J. communis sibirica. The generally accepted 

 vernacular name of this species, "common juniper," is derived from 

 its technical name. Occasionally it is called "dwarf juniper" and 

 "ground cedar." 



DISTINGUISHING CHARACTERISTICS. 



Throughout its wide range in North America common juniper 

 attains tree size only in a few counties of southern Illinois, where it 

 grows to a height of from 15 to nearly 25 3 feet and a diameter of 

 from 6 to 8 inches. Elsewhere it is a shrub less than 5 feet high, 

 with numerous slender, half-prostrate stems forming a tangled mass 

 from 5 to 10 feet across. Its very unsymmetrical trunk has con- 

 spicuous rounded ridges and intervening grooves at and near the 

 ground. It is clear of branches for only a few feet, and the crown, 

 narrow and very open, has short, slender branches trending upward. 

 The bark, in color a deep chocolate brown tinged with red, is less 

 than one-eighth of an inch thick and composed of loosely attached, 

 extremely thin scales. 



The dark, lustrous green, keenly pointed, needlelike, or narrow, 

 lance-shaped leaves (Pis. VI, VII), are chalky white on their upper 



1 The prostrate, high mountain form of this species must be considered a variety, J. communis sibirica 

 (Burgsd.) Rydberg. It differs from J. communis L. in being wholly prostrate, and also in the fact that 

 its foliage is often shorter than that of J. communis. 



Another prostrate shrub juniper, more or less common from Maine and New Foundland to Hudson 

 Bay and the eastern slopes of the Rockies in Montana is Juniperus sabina prostrata (Pers.) Loudon. J. 

 sabina, of which this prostrate shrub is held to be a variety, is generally distributed through central and 

 southern Europe and Siberia. It is distinguished from the North American variety by being a strictly 

 upright shrub, or occasionally a small tree. The freshly cut wood and crushed twigs of these plants have 

 a characteristic, rather disagreeable odor. They are further distinguished from J. communis and its variety 

 J. communis sibirica by having the short scalelike, pointed leaves in alternately arranged pairs, the points 

 of the leaves more or less spreading and free. The needlelike leav es of J. communis are arranged in groups 

 of three. 



2 It also grows naturally in northern, central, and eastern Asia, as well as in northern and central Europe. 

 8 In Germany and Norway it is said to attain 30 to 40 feet or more in height. 



