UNITED STATES DEPARTMENT OF AGRICULTURE 



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BULLETIN No. 207 



Contribution from the Forest Service 

 HENRY S. GRAVES, Forester 



Washington, D. C. 



PROFESSIONAL PAPER. 



July 17, 1915. 



THE CYPRESS AND JUNIPER TREES OF THE ROCKY 

 MOUNTAIN REGION. 



By George B. Sudworth, Dendrologist. 



CONTENTS. 



Scope of the bulletin 1 



Class and family relationship of cypresses 



and junipers 3 



Generic characteristics of cypresses 4 



Arizona cypress ( Cupressus arizonica 



Greene) 5 



Smooth cypress ( Cupressus glabra Sud- 

 worth) 8 



Generic characteristics of junipers 11 



Common juniper (Juniperus communis 



Linnaeus) 13 



Western juniper (Juniperus occidentalis 



Hooker) 15 



Mountain red cedar (Juniperus scopu- 

 lorum Sargent) 18 



Generic characteristics of junipers — Cont'd. 

 One-seed juniper (Juniperus monosperma 



(Engelm.) Sargent) 20 



Mountain cedar (Juniperus sabinoides 



(H., B. andK.) Nees) 23 



Utah juniper (Juniperus utahensis 



(Engelm.) Lemmon) 26 



Knight juniper(/M,«iperws knightii NelsoD) 26 

 Big-berried juniper (Juniperus megalo- 



carpa Sudworth) 28 



Alligator juniper (Juniperus pachyphlaa 



Torrey) 30 



Drooping juniper (Juniperus flaccida 



Schlechtendal) 2 



Key to species 36 



SCOPE OF THE BULLETIN. 



This bulletin describes the distinguishing characters, geographic 

 distribution, and forest habits of all the known species of cypress 

 (Cupressus) and juniper (Juniperus) growing within the Rocky Moun- 

 tain region. The region embraces western North and South Dakota, 

 Montana, Idaho, Wyoming, western Nebraska, Colorado, Utah, 

 Nevada, Arizona, New Mexico, and western Texas. Such outly- 

 ing regions as the Dakotas, western Nebraska, and western Texas 

 are included because a few species extend from the main Rocky 

 Mountain region into them. For the same reason Canadian territory 

 lying directly north of the Rockies and Mexican territory adjacent 

 to our Southwest are also included. Canada has no cypress or juniper 

 trees that do not occur at some point within the United States. 

 Mexico, on the other hand, has both cypress and juniper trees that 



84703°— Bull. 207—15 1 



