1	Leaves of 1 kind, subulate, with basal abscission zone, spreading; cones axillary (Juniperus sect. Juniperus). ..		1 Juniperus communis
+	Leaves of 2 kinds, whip (subulate, without basal abscission zone) and scalelike; cones terminal (Juniperus sect. Sabina Spach).		(2)
2 (1)	Margins of leaves entire (at 20×) or, if with irregular teeth (at 40×), then scalelike leaves acuminate at apex.		(3)
+	Margins of leaves denticulate (at 20×), scalelike leaves usually obtuse to acute at apex (sometimes mucronate in Juniperus deppeana or acuminate in J. monosperma).		(6)
3 (2)	Margins of leaves with irregular teeth (at 40×), scalelike leaves acuminate at apex; seed cones with 4-13 seeds, tan-brown to brownish purple when mature; branches as well as branchlets flaccid. .		2a var. flaccida
+	Margins of leaves entire (at 20× and 40×), scalelike leaves obtuse to acute or apiculate at apex; seed cones with 1-3 seeds, blue-black to brownish blue when mature; branches not drooping, but branchlets often flaccid.		(4)
4 (3)	Prostrate to decumbent shrubs; scalelike leaves apiculate at apex; peduncles generally curved.		3 Juniperus horizontalis
+	Upright trees; scalelike leaves obtuse to acute at apex; peduncles generally straight.		(5)
5 (4)	Scalelike leaves not overlapping, or, if so, by not more than 1/5 their length, apex obtuse to acute; bark of larger branchlets exfoliating in plates; seed cones maturing in 2 years, of 2 distinct sizes.		4 Juniperus scopulorum
+	Scalelike leaves overlapping by more than 1/4 their length, apex acute (to bluntly obtuse in var. silicicola, se United States); bark of larger branchlets usually exfoliating in strips; seed cones maturing in 1 year, of 1 size.		5 Juniperus virginiana
6 (2)	Seed cones with 3-6 seeds, fibrous to obscurely woody; bark exfoliating in rectangular plates, branchlets erect (rarely bark exfoliating in thin strips, branchlets then flaccid).		6a var. deppeana
+	Seed cones with 1-3 seeds, fleshy or resinous to fibrous; bark exfoliating in thin strips, branchlets erect.		(7)
7 (6)	Leaves with raised hemispheric glands (particularly obvious on whip leaves).		7 Juniperus ashei
+	Leaves with ovate, elliptic, elongate, or inconspicuous glands (or glands round on scalelike leaves only).		(8)
8 (7)	Seed cones blue to blue-black, with 2(-3) seeds, maturing in 2 years; bark of branchlets greater than 10 mm diam. exfoliating in scales or flakes; single-stemmed trees to 20(-30) m.		8 Juniperus occidentalis
+	Seed cones variously colored, but with brownish or reddish hue, even when some blue is present, with 1(-2) seeds, usually maturing in 1 year; bark of branchlets greater than 10 mm diam. usually exfoliating in strips or smooth; usually multistemmed shrubs or trees to 12 m.		(9)
9 (8)	Abaxial glands inconspicuous because embedded in leaf; monoecious.		9 Juniperus osteosperma
+	Abaxial glands conspicuous; dioecious (very rarely monoecious).		(10)
10 (9)	Seed cones mostly 9-10 mm diam., bluish brown, glaucous; branchlets about as wide as length of scalelike leaves; scalelike leaves closely appressed, abaxial surface generally flattened; branchlets terete.		10 Juniperus californica
+	Seed cones mostly 6-8 mm diam., reddish blue to brownish blue, rose to pinkish, or copper to copper-red, glaucous or not; branchlets ca. 2/3 as wide as length of scalelike leaves; scalelike leaves with apex spreading, abaxial surface raised; branchlets generally 3-4(-6)-sided.		(11)
11 (10)	Seed cones reddish blue to brownish blue; fewer than 1/5 of whip-leaf glands with evident white exudate.		11 Juniperus monosperma
+	Seed cones rose to pinkish or copper to copper-red; 1/4 or more of whip-leaf glands with evident white exudate.		(12)
12 (11)	Seed cones rose to pinkish, glaucous; adaxial surface of leaves glaucous.		12 Juniperus coahuilensis
+	Seed cones copper to copper-red, not glaucous; adaxial surface of leaves not glaucous.		13 Juniperus pinchotii