3.
Juniperus horizontalis
Moench, Methodus. 699. 1794.
Creeping juniper, savinier, genévrier horizontal
Juniperus horizontalis
var.
douglasii
hort.;
J
.
horizontalis
var.
variegata
Beissner
Shrubs dioecious, prostrate to decumbent; crown depressed. Bark brown, exfoliating in thin strips, that of small branchlets (5--10 mm diam.) smooth, that of larger branchlets exfoliating in wide strips or plates. Branches creeping; branchlets erect, 3--4-sided in cross section, ca. 2/3 or less as wide as length of scalelike leaves. Leaves green but turning reddish purple in winter, abaxial gland elliptic, conspicuous, exudate absent, margins entire (at 20´ and 40´); whip leaves 4--8 mm, not glaucous adaxially; scalelike leaves 1.5--2 mm, mostly overlapping to 1/3 their length, apex rounded or obtuse to acute and apiculate, spreading. Seed cones mostly maturing in 2 years, of 2 distinct sizes, generally with curved peduncles, globose to ovoid, 5--7 mm, blue-black to brownish blue when mature, lightly glaucous, soft and resinous, with 1--2(--3) seeds. Seeds 4--5 mm. 2 n = 22.
Sand dunes, sandy and gravelly soils, prairies, slopes, rock outcrops, and stream banks; 0--1000 m; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Ill., Iowa, Maine, Mass., Mich., Minn., Mont., Nebr., N.H., N.Y., N.Dak., S.Dak., Vt., Wis., Wyo.
Juniperus horizontalis , a prostrate species, hybridizes with the trees J . virginiana and J . scopulorum (R. P. Adams 1983; N. C. Fassett 1945; M. Palma-Otal et al. 1983) and is closely related to both. The hybrid between J . horizontalis and J . scopulorum has been named J . ´ fassettii Boivin.
