Juniperus scopulorum, the Rocky Mountain juniper, is a species of juniper native to western North America, from southwest Canada to the Great Plains of the United States. Description Juniperus scopulorum is a small evergreen conifer reaching , rarely to 20 m, tall, with a trunk up to , rarely 2 m, in diameter. The shoots are slender, diameter. The leaves are arranged in opposite decussate pairs, or occasionally in whorls of three; the adult leaves are scale-like, 1–3 mm long (to 5 mm on lead shoots) and broad. The juvenile leaves (on young seedlings only) are needle-like, 5–10 mm long. The seed cones are berry-like, globose to bilobed, in diameter, dark blue with a pale blue-white waxy bloom, and contain two seeds (rarely one or three); they are mature in about 18 months and are eaten by wildlife. The pollen cones are long, and shed their pollen in early spring. It is dioecious, producing cones of only one sex on each tree. Rocky Mountain juniper is an aromatic plant. Essential oil extracted from the trunk is prominent in cis-thujopsene, α-pinene, cedrol, allo-aromadendrene epoxide, (E)-caryophyllene, and widdrol. Limb essential oil is primarily α-pinene and leaf essential oil is primarily sabinene. One particular individual, the Jardine Juniper in Utah, is thought to be over 1,500 years old, while a dead trunk found in New Mexico was found to have 1,888 rings; older trees in the same area are suspected to exceed 2,000 years. Similar species Juniperus scopulorum is closely related to J. virginiana, and often hybridizes with it where their ranges meet on the Great Plains. Hybrids with J. horizontalis also occur. Isolated populations of junipers occur close to sea level in the Puget Sound area in Washington Park near Anacortes and southwestern British Columbia in a park called Smugglers Cove. In both locales, there are a considerable number of young and old specimens. Previously included in J. scopulorum, it has recently been shown to be genetically distinct, and has been described as a new species J. maritima. It is a cryptic species barely distinguishable on morphology, though it does differ in phenology, with the cones maturing in 14–16 months, and often has the tips of the seeds exposed at the cone apex. Taxonomy Scopulorum means "of the mountains". Distribution and habitat The species is native to western North America, in Canada in south British Columbia and southwest Alberta, in the United