The Gymnosperm Database


J. horizontalis in habitat atop Buck Hill in Theodore Roosevelt National Park in North Dakota. Although the elevation here is only 870 m, the exposure is severe in winter, and the area contains vegetation typical of alpine areas [C.J. Earle, 2014.07.01].


Closer view of the plant shown above, featuring foliage and nearly mature seed cones [C.J. Earle, 2014.07.01].


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Conservation status

Juniperus horizontalis

Moench 1794

Common names

Creeping juniper, savinier, genévrier horizontal (Adams 1993), Bar Harbor juniper in Maine (V. Dinets, e-mail 18-Oct-2003).

Taxonomic notes

Syn: J. communis var. jackii (Silba 1986); Juniperus horizontalis var. douglasii hort.; J. horizontalis var. variegata Beissner. "Juniperus horizontalis, a prostrate species, hybridizes with the trees J. virginiana and J. scopulorum (Adams 1983; Fassett 1945; 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" (Adams 1993).


"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. 2n = 22" (Adams 1993).

Distribution and Ecology

Canada: all provinces and territories; France: St. Pierre and Miquelon; USA: Alaska, Montana, Wyoming, Nebraska, South Dakota, North Dakota, Minnesota, Iowa, Illinois, Wisconsin, Michigan, New York, Vermont, Massachusetts, New Hampshire and Maine; at 0-1000 m on sand dunes, sandy and gravelly soils, prairies, slopes, rock outcrops, and stream banks (Adams 1993). See also Thompson et al. 1999. Hardy to Zone 4 (cold hardiness limit between -34.3°C and -28.9°C) (Bannister and Neuner 2001).

Distribution data. Data sources (click on data points to view) include my observations (accompanied by a list of associated gymnosperm taxa), GBIF (2014; accompanied by name or abbreviation of the collecting institution), Tropicos (2014; accompanied by detailed specimen data), the New York Botanical Garden (2014; accompanied by detailed specimen data), and the Consortium of Pacific Northwest Herbaria (2014; accompanied by detailed specimen data).

Big tree

Not very big! In fact J. horizontalis currently holds the record as the smallest conifer, since I have found cone-bearing individuals only 4 cm tall.







Adams, Robert P. 1993. Juniperus. Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Vol. 2. Oxford University Press. This document is available online. Go to, click on "Flora of North America," and search for "Juniperus."

See also

Farjon (2005) provides a detailed account, with illustrations.

Last Modified 2017-12-29