1. Juniperus communis Linnaeus, Sp. Pl.  2: 1040.  1753.  
Common juniper, genévrier commun  
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. 2 n  = 22.
Varieties 5 (3 in the flora): North America, Eurasia.
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.