Rocky Mountain juniper

Description

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. Juniperus scopulorum is a small evergreen conifer reaching 5–15 metres (16–49 ft), rarely to 20 m, tall, with a trunk up to 1 m (3 ft 3 in), rarely 2 m, in diameter. The shoots are slender, 0.7–1.2 millimetres (1⁄32–1⁄16 in) 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 1–1.5 mm (1⁄32–1⁄16 in) broad. The juvenile leaves (on young seedlings only) are needle-like, 5–10 mm long. The seed cones are berry-like, globose to bilobed, 5–9 mm (3⁄16–11⁄32 in) 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 2–4 mm (3⁄32–5⁄32 in) 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. The species is native to western North America, in Canada in south British Columbia and southwest Alberta, in the United States sporadically from Washington east to North Dakota, south to Arizona and also locally western Texas, and northernmost Mexico from Sonora east to Coahuila. It grows at altitudes of 500–2,700 m (1,600–8,900 ft) on dry soils, often together with other juniper species. It requires about 25 centimetres (9+7⁄8 in) of annual precipitation. Junipers are coniferous trees and shrubs in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arctic, south to tropical Africa, throughout parts of western, central and southern Asia, east to eastern Tibet in the Old World, and in the mountains of Central America.