Juniperus communis

Linnaeus

Sp. Pl. 2: 1040. 1753.

Common names: Common juniper genévrier commun
Illustrated
Treatment appears in FNA Volume 2.

Shrubs or small trees dioecious, to 4 m (if trees, to 10 m), multistemmed, decumbent or rarely upright; crown generally depressed. Bark brown, fibrous, exfoliating in thin strips, that of small branchlets (5–10 mm diam.) smooth, that of larger branchlets exfoliating in strips and plates. Branches spreading or ascending; branchlets erect, terete. Leaves green but sometimes appearing silver when glaucous, spreading, abaxial glands very elongate; adaxial surface with glaucous stomatal band; apex acute to obtuse, mucronate. Seed-cones maturing in 2 years, of 2 distinct sizes, with straight peduncles, globose to ovoid, 6–13 mm, bluish black, glaucous, resinous to obscurely woody, with 2–3 seeds. Seeds 4–5 mm. 2n = 22.

Distribution

Alta., B.C., Man., N.B., N.S., N.W.T., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Conn., Ga., Idaho, Ill., Ind., Maine, Mass., Mich., Minn., Mont., N.C., N.Dak., N.H., N.Mex., N.Y., Nev., Ohio, Oreg., Pa., R.I., S.C., S.Dak., Utah, Va., Vt., Wash., Wis., Wyo., Eurasia

Discussion

Juniperus communis is the most widespread juniper species, and many subspecies and varieties have been described. A major study, including chemical characters, is needed to clarify the taxonomy. J. D. A. Franco (1962) recognized four subspecies (here considered varieties); two of these—var. communis and var. hemisphaerica (J. Presl & C. Presl) Parlatore—do not occur in the flora and a fifth, recognized here, was not treated by Franco.

The seed cones of Juniperus communis are used to flavor gin.

Varieties 5 (3 in the flora).

Selected References

None.

Key

1 Seed cones 9–13 mm, longer than leaves. Juniperus communis var. megistocarpa
1 Seed cones 6–9 mm, shorter than leaves. > 2
2 Glaucous stomatal band on adaxial leaf surface 2 or more times as wide as each green marginal band; spreading to matlike shrubs; leaves linear-lanceolate, to 2 mm wide, apex acute to obtuse and mucronate. Juniperus communis var. montana
2 Glaucous stomatal band on adaxial leaf surface about as wide as each green marginal band; prostrate, low shrubs with ascending branchlet tips (occasionally spreading shrubs, rarely small trees); leaves linear, to 1.6 mm wide, apex acute and mucronate to acuminate. Juniperus communis var. depressa
... more about "Juniperus communis"
not +  and visible +
Mucronate (?) +, Acute (?) +  and Obtuse (?) +
Robert P. Adams +
Linnaeus +
long-lived +
exfoliating +
ascending;spreading +
inconspicuous +  and undifferentiated +
Common juniper +  and genévrier commun +
0.6 cm6 mm <br />0.006 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
globose +  and ovoid +
depressed +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, N.W.T. +, Nfld. and Labr. (Nfld.) +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Conn. +, Ga. +, Idaho +, Ill. +, Ind. +, Maine +, Mass. +, Mich. +, Minn. +, Mont. +, N.C. +, N.Dak. +, N.H. +, N.Mex. +, N.Y. +, Nev. +, Ohio +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Utah +, Va. +, Vt. +, Wash. +, Wis. +, Wyo. +  and Eurasia +
decurrent +  and scale-like +
petioled +, sessile +, twisted +  and simple +
divergent +  and opposite +
green but sometimes appearing silver +
persisting +
3 (?) +  and 5 (?) +
subulate +
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 />) +
fibrous;woody +
peltate +  and complex +
cuneate +  and oblong +
fleshy +  and woody +
overlapping +
persistent +
coalesced +
fibrous +  and obscurely woody +
1 +  and 2 +
2 +  and 3 +
round +  and faceted +
Illustrated +
flattened +
Juniperus sect. Oxycedrus +
Juniperus communis +
Juniperus sect. Juniperus +
species +
flattened +, angled +  and terete +
tree +  and shrub +
upright +  and decumbent +
asymmetric +  and symmetric +