Juniperus scopulorum

Sargent

Gard. & Forest 10: 420, fig. 54. 1897.

Common names: Rocky Mountain juniper Rocky Mountain redcedar
Synonyms: Sabina scopulorum (Sargent) Rydberg
Treatment appears in FNA Volume 2.

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. 2n = 22.


Habitat: Rocky soils, slopes, and eroded hillsides
Elevation: 1200–2700 m (0 m at Vancouver Island and Puget Sound)

Distribution

V2 47-distribution-map.gif

Alta., B.C., Ariz., Colo., Idaho, Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Utah, Wash., Wyo., n Mexico

Discussion

Juniperus scopulorum hybridizes with its eastern relative J. virginiana in zones of contact in the Missouri River basin (C. W. Comer et al. 1982) and with J. horizontalis (J. × fassettii Boivin; N. C. Fassett 1945). Relictual hybridization with J. virginiana is known in the Texas panhandle (R. P. Adams 1983).

Selected References

None.

Lower Taxa

None.

... more about "Juniperus scopulorum"
elongate +  and hemispheric +
spreading +  and appressed +
Obtuse (?) +  and Acute (?) +
Robert P. Adams +
Sargent +
long-lived +
exfoliating +
spreading;ascending +
angled +  and terete +
inconspicuous +  and undifferentiated +
Rocky Mountain juniper +  and Rocky Mountain redcedar +
resinous +  and glaucous +
dark blue-black +  and light blue +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
globose +  and 2-lobed +
conic +  and occasionally rounded +
Alta. +, B.C. +, Ariz. +, Colo. +, Idaho +, Mont. +, Nebr. +, Nev. +, N.Mex. +, N.Dak. +, Oreg. +, S.Dak. +, Utah +, Wash. +, Wyo. +  and n Mexico +
1200–2700 m (0 m at Vancouver Island and Puget Sound) +
Rocky soils, slopes, and eroded hillsides +
decurrent +  and scale-like +
petioled +, sessile +, twisted +  and simple +
not overlapping +  and overlapping +
blue-gray +, blue +, glaucous +, light +  and dark green +
persisting +
not /5 +  and not 1 +
3 (?) +  and 5 (?) +
keeled +  and rounded +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
spheric;oblong +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Gard. & Forest +
fibrous;woody +
peltate +  and complex +
cuneate +  and oblong +
fleshy +  and woody +
overlapping +
persistent +
coalesced +
fibrous +  and obscurely woody +
1 +  and 2 +
round +  and faceted +
flattened +
Sabina scopulorum +
Juniperus scopulorum +
Juniperus sect. Sabina +
species +
flattened +, angled +  and terete +
upright +  and decumbent +
asymmetric +  and symmetric +