Juniperus communis / common juniper

Juniperus communis, as described in 1753 by Carl Linnaeus (or Carolus Linnæus) (1707–1778), Species Plantarum 2, is commonly known as the common juniper, is a species in the genus Juniperus, in the family Cupressaceae. It has the largest range of any woody plant, throughout the cool temperate Northern Hemisphere from the Arctic, south in mountains to around 30°N latitude in North America, Europe and Asia,

common juniper, <em>Juniperus communis </em>a drawing by Bildagentur-online
common juniper, Juniperus communis a drawing by Bildagentur-online

Description. Common juniper is an evergreen coniferous shrub or small tree, with very variable structure, most often seen as a low, spreading shrub, but occasionally growing as a tree reaching mature heights of 30 feet (10 m) tall. This species is dioecious, with male and female cones on separate plants, which are wind pollinated.

  • It has needle-like leaves in whorls of three; the leaves are green, with a single white stomatal band on the inner surface.
  • The seed cones are berry-like, and green in color when young, ripening in 18 months to purple-black with a blue, waxy coating; they are spherical, each measuring 0.12 to 0.48 inch (4 – 12 mm) in diameter, and usually have three (occasionally six) fused scales, each scale with a single seed.
  • The pollen cones are yellow, measuring 0.08 to 0.12 inch (2 – 3 mm) long, and fall soon after shedding their pollen in March and April.
  • The seeds are dispersed when birds eat the cones, digesting the fleshy scales and passing the hard seeds in their droppings.

Distribution. As stated earlier, this species is the most widespread conifer in the world, native to temperate Eurasia, and North America N of Mexico, occupying an extraordinarily range of habitats.

Hardy to USDA Zone 3 — cold hardiness limit between -40° and -30°F (-39.9° and -34.4°C).

Attribution from: Aljos Farjon; A monograph of Cupressaceae and Sciadopitys; ©2005, Royal Botanic Gardens, Kew

Juniperus communis Common juniper, Mt Baker, WA
Juniperis communis 'Green Carpet' cultivar photographed in Brunswick, ME, 2013
Photo by Sean Callahan
Juniperis communis 'Green Carpet' cultivar photographed in Brunswick, ME, 2013
Photo by Sean Callahan