PINACEAE 



The Junipers 

 Characteristics of the Genus Juniperus L. 



HABIT. Evergreen, aromatic small trees or shrubs. 



LEAVES. Persistent for several years, sessile, aromatic; 

 needle-like or awl-shaped on young growth; of three types on 

 older growth; (1) ternate, spreading, and entirely needle-like 

 or subulate; (2) decussate, appressed, decurrent, and entirely 

 scalelike; (3) a combination of the preceding types. 



FLOWERS. Dioecious (rarely monoecious) ; minute and 

 inconspicuous; male yellow, solitary, of numerous ternate or 

 decussate stamens; female of 3-8 decussate or ternate pointed 

 scales, some or all bearing 1 or 2 ovules. 



FRUIT. A berry-like, succulent, indehiscent cone, formed 

 by coalescence of flower scales; subtended by persistent flower 

 bracts; maturing in 1-3 years. Seed: 1-21 in cone, ovoid, un- 

 winged, marked at base by a scar (hilum). 



BUDS. Small, naked and covered by leaves (scaly in dwarf 

 juniper) . 



BARK. Thin, soft, fibrous, and shreddy (brittle, thick and 

 divided into nearly square plates in alligator juniper). 



WOOD. Durable; weak; close-grained; aromatic; heartwood 

 red-purple to brown; sapwood whitish. 



SILVICAL CHARACTERS. Exceedingly variable; mostly 

 intolerant; slow-growing; long-lived; seed disseminated by 

 birds or mammals; deep lateral roots. 



GENERAL. This genus contains 40-60 species widely scat- 

 tered through the Northern Hemisphere, with 13 species native 

 to the United States. Only J. virginiana is of any commercial 

 importance, although several other species form conspicuous 

 parts of the vegetation. Two appear as small shrubs: 



(1) The dwarf juniper, Juniberus communis L., while circumpolar 

 and extending through most of the United States and Canada, 

 attains tree size only in New England and southern Illinois; this 

 species has ternate leaves, Vz-Vz inch long, which are all needle- 

 like, scaly buds, and axillary flowers ; the prostrate, high mountain 

 form has been designated J. communis var. montana Ait. {J. com- 

 munis var. sibirica Rydb.). 



(2) The prostrate juniper, J. horizontalis Moench, entering 

 the United States from the north, diff'ers from dwarf juniper 

 in having closely appressed, decussate leaves, V6-I4 inch long. 

 This species often forms dense creeping mats. 



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