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Juniperus scopulorum
Sargent 1897
Common NamesRocky Mountain juniper, mountain red cedar, weeping juniper (2), Rocky Mountain redcedar (3).
Taxonomic notesSyn: Sabina scopulorum (Sargent) Rydberg (3). Distribution contiguous with and morphology very similar to J. virginiana . J. scopulorum hybridizes with J. virginiana "in zones of contact in the Missouri River basin (Comer et al. 1982) and with J. horizontalis ( J. × fassettii Boivin; Fassett 1945 ). Relictual hybridization with J. virginiana is known in the Texas panhandle (Adams 1983)" (3).
Description"Trees dioecious, to 20 m, single-stemmed (rarely multistemmed); crown conic to occasionally rounded. Bark brown, exfoliating in thin strips, that of small branchlets (5-10 mm diam.) smooth, that of larger branchlets exfoliating in plates. Branches spreading to ascending; branchlets erect to flaccid, 3-4-sided in cross section, ca. 2/3 or less as wide as length of scalelike leaves. Leaves light to dark green but often glaucous blue or blue-gray, abaxial gland elliptic, conspicuous, exudate absent, margins entire (at 20× and 40×); whip leaves 3-6 mm, not glaucous adaxially; scalelike leaves 1-3 mm, not overlapping to overlapping by not more than 1/5 their length, keeled to rounded, apex obtuse to acute, appressed or spreading. Seed cones maturing in 2 years, of 2 distinct sizes, generally with straight peduncles, globose to 2-lobed, 6-9 mm, appearing light blue when heavily glaucous, but dark blue-black beneath glaucous coating when mature (or tan beneath glaucous coating when immature), resinous to fibrous, with (1)2(3) seeds. Seeds 4-5 mm. 2 n = 22" (3).RangeCanada, USA and Mexico; British Columbia (Vancouver Is. to the Rockies), Alberta (rare), S in Rockies through Montana, Wyoming, Colorado and New Mexico to W Texas, S-C Arizona and N Mexico; also in Washington, E Oregon, E Nevada and Utah; also on mountains E of the Rocky Mountain Front in Montana, North Dakota, South Dakota and Nebraska (2). Found at 0-2700 m elevation, mostly on rocky soils (3). See also (4).Big TreeDiameter 200 cm, height 12 m, crown spread 6 m, located in Cache National Forest, UT ( American Forests 1996 ).OldestA log (specimen CRE 175) with crossdated inner date 29 BC and outer date AD 1859 was collected in July 1993 by Henri Grissino-Mayer, James Riser, Rex Adams, and Ikuo Furukawa. This indicates that the tree lived for more than 1888 years. The specimen is from El Malpais National Monument in New Mexico, an area where all native conifer species attain exceptional ages. Grissino-Mayer reports (pers. comm., January 1997) that "at El Malpais National Monument, we believe that there exist some 2000+ year old JUSCs as well."DendrochronologyEthnobotanyObservationsHave seen widely, notably in the San Juan Islands of WA and in a dendrochronological collection in NV (1).RemarksCitations(1) Holmes et al. 1986 .(2) Peattie 1950 . (3) Adams, Robert P. in Flora of North America online . (4) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html , accessed 22-Jan-2000.
See also
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This page is from the Gymnosperm Database
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