Juniperus communis

Juniperus communis, the common juniper, is a species of small tree or shrub in the cypress family Cupressaceae. An evergreen conifer, it has the largest geographical range of any woody plant, with a circumpolar distribution throughout the cool temperate Northern Hemisphere. Juniperus communis is highly variable in form, ranging from —rarely —tall to a low, often prostrate spreading shrub in exposed locations. It has needle-like leaves in whorls of three; the leaves are green, with a single white stomatal band on the inner surface. It never attains the scale-like adult foliage of other members of the genus. It is dioecious, with male and female cones on separate plants so requiring wind pollination to transfer pollen from male to female cones. Male trees or shrubs naturally live longer than female trees or shrubs; a male tree or shrub can live more than 2000 years. The male cones are yellow, long, and fall soon after shedding their pollen in March–April. The fruit are berry-like cones known as juniper berries. They are initially green, ripening in 18 months to purple-black with a blue waxy coating; they are spherical, diameter, and usually have three (occasionally six) fleshy fused scales, each scale with a single seed. The seeds are dispersed when birds eat the cones, digesting the fleshy scales and passing the hard, unwinged seeds in their droppings. The juniper berry oil is composed largely of monoterpene hydrocarbons such as α-pinene, myrcene, sabinene, limonene and β-pinene. As to be expected from the wide range, J. communis is very variable, with several infraspecific taxa; delimitation between the taxa is still uncertain, with genetic data not matching morphological data well. subsp. communis – Common juniper. Usually an erect shrub or small tree; leaves long; cones small, 5–8 mm, usually shorter than the leaves; found at low to moderate altitude in temperate climates subsp. communis var. communis – Europe, most of northern Asia subsp. communis var. depressa – North America, Sierra Nevada in California subsp.