| Juniperus osteosperma | |
|---|---|
| A Utah Juniper showing distinctive shape and leaves | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Cupressaceae |
| Genus: | Juniperus |
| Species: | J. osteosperma |
| Binomial name | |
| Juniperus osteosperma (Torr.) Little |
|
Juniperus osteosperma (Utah Juniper; syn. J. utahensis) is a shrub or small tree reaching 3-6 m (rarely to 9 m) tall. It is native to the southwestern United States, in Utah, Nevada, Arizona, western New Mexico, western Colorado, Wyoming, southern Montana, southern Idaho and eastern California. It grows at moderate altitudes of 1,300-2,600 m, on dry soils, often together with Pinus monophylla.
The shoots are fairly thick compared to most junipers, 1.5-2 mm diameter. The leaves are arranged in opposite decussate pairs or whorls of three; the adult leaves are scale-like, 1-2 mm long (to 5 mm on lead shoots) and 1-1.5 mm broad. The juvenile leaves (on young seedlings only) are needle-like, 5-10 mm long. The cones are berry-like, 8-13 mm in diameter, blue-brown with a whitish waxy bloom, and contain a single seed (rarely two); they are mature in about 18 months. The male cones are 2-4 mm long, and shed their pollen in early spring. It is largely monoecious with both sexes on the same plant, but around 10% of plants are dioecious, producing cones of only one sex.
The plants frequently bear numerous galls caused by the Juniper Tip Midge Oligotrophus betheli (Bibionomorpha: Cecidomyiidae); these are conspicuous pale violet-purple, produced in clusters of 5-20 together, each gall 1-2 cm diameter, with dense modified spreading scale-leaves 6-10 mm long and 2-3 mm broad at the base. Seeds are dispersed by Jackrabbits (mostly the Black-tailed Jackrabbit Lepus californicus spp.) rodents and to a lesser extent by coyotes (Canis latrans).