The seed cones of Juniperus communis are used to flavor gin.
Juniperus communis, the common juniper—also known as ground juniper (although ground juniper is often classified as var. depress)—is a wide-ranging shrub or small tree in the Cupressaceae (cypress family) native to cool temperate areas in the Northern Hemisphere, and may have one of the widest distributions of any woody plant. It is widely found in natural habitats, where its seed cones (“juniper berries”) and foliage are an important food source for numerous species of songbirds, ground-nesting birds, small mammals, and ungulate browsers, and there are dozens of horticultural cultivars for landscape and ornamental use (varying in form from spire-like to prostrate and trailing, and ranging in foliage color from blue to green to golden yellow). It is not used for timber due to its shrubby habit. The species has complex intraspecific variation, and according to one recent treatment, includes 7 major varieties: 3 in North America; 2 in northern Europe; and 1 in Japan. Some varieties, however, have very restricted habitat and distribution—for example, var. charlottensis occurs on Queen Charlotte island in British Columbia, Canada, in nearby Alaskan islands, and on adjacent parts of the British Columbia and Alaskan coasts—and are threatened by habitat degradation. Within North America, the ground juniper (var. depressa) is the most wide-ranging, extending through the northeastern U.S. and across much of Canada into Alaska, as well as extending south into the Rocky Mountains. It tends to grow well in disturbed areas, so its distribution has expanded during the past century. Juniperus communis is a shrub or small tree which has variable growth form, ranging from a low, spreading or upright shrub to a small tree, usually to 5 m (16.25 ft,) tall, but occasionally reaching heights up to 10 m (33 feet). Its leaves are sharp, needle-like but somewhat flattened, and ternate (occurring in threes), with a single white stomatal band on the upper side and a slight keel (ridge) on the underside. The species is dioecious—male and wind-pollinated female flowers grow on separate plants, and only female flowers develop seed cones, which have fused scales and are round and berry-like, up to 1 cm (0.5 in) in diameter. Seed cones ripen to blue or black with a glaucous (waxy) coating, and typically contain 3 to 6 seeds. The seed cones of various Juniperus species make up 2 to 5% of the diet of 66 species of North American mammals, and are also edible by humans—they add the characteristic flavor to gin, and they are featured in teas and herbal supplements. The species is often bird-dispersed, as seed germination rates may be higher following passage through a bird gut. (Adams 2008, Bailey et al. 1976, Martin et al. 1951, Royal Horticultural Society 2012.)
In a Scottish study, common juniper was killed by 1,472 oF (800 oC) heat treatment when heath was burned. Plants made only "feeble regrowth" when burned at 1,112 oF (600 oC). However, following treatment at 752 oF (400 oC), new shoots were produced [82].
Following "light" (less than 50% litter reduction) fires
in forested areas of western Montana, burned sites often
exhibit minimal shrub damage and have at least some
surviving common juniper [120]. Common juniper averaged 6.7%
cover 3 years after a
light burn in Montana [120]. Laboratory heating experiments on
common juniper plants from Scottish heath showed that growth could
take place after heating only if some of the basal green branches remain
alive [82]: effect of temperature* on vegetative regrowth after heating
400oC 600oC 800oC
mean # sprouts per plant
3 months after treatment 5 4 0
height of veg. regrowth (cm)
17 months after treatment 8 6 0
oven-dry biomass per plant of
veg. regrowth (grams) 3 0.8 0
17 months after treatment
*"temperature maintained for about 2 minutes"
Most fires kill common juniper [25], leading to the
slow postfire recovery typical of this species. In northern
Canada, common juniper is generally absent from burned areas, but
may grow in small refugia within burned areas [69].
Postfire recovery of common juniper is generally slow. The following
table gives the density and
frequency of occurrence for common juniper in stands of different ages
in 2 Colorado forest types [21]:
--------------------------------------------------
Stand Spruce Freq. Stand Lodgepole Freq.
age -fir age density
after density after
fire fire
--------------------------------------------------
1 --- --- 1 --- ---
2 --- --- 2 --- ---
8 --- --- 8 --- ---
8 0.2 20 8 --- ---
18 0.2 20 18 0.2 20
74 2.7 70 18 0.8 20
200 0.2 8 18 0.4 20
280 0.6 40 45 0.8 40
290 0.4 20 85 2.0 100
85 0.8 60
108 0.6 60
115 0.4 40
190 1.4 60
248 0.8 20
251 1.3 30
257 3.4 85
-------------------------------------------------
For further information on prescribed fire use and common juniper's response to
fire, see Fire Case Studies.
The following Research Project Summaries provide information on prescribed
fire use and postfire response of plant community species including common
juniper:
Common juniper is listed as a species of state concern in South Carolina [119]. Juniperus communis var. depressa is state-ranked as extremely rare in Virginia [133].
The shade and cover value of common juniper tends to be greatest for birds and small mammals. It provides especially good nesting cover for Merriam's wild turkeys in the Black Hills of South Dakota [59,110]. In New Jersey, it provides winter roosts for short-eared owls [17]. In the Northwest Territories, common juniper branches are used in woodrat nests [112].
The cover value of common juniper for wildlife species has been rated as follows [32]:
CO MT ND UT WY Pronghorn ---- ---- ---- poor poor Elk ---- ---- ---- poor fair Mule deer ---- poor good fair fair White-tailed deer ---- poor good ---- fair Small mammals fair ---- ---- good good Small nongame birds fair ---- good good good Upland game birds ---- ---- ---- good good Waterfowl ---- ---- ---- poor poorCommon juniper is a native, evergreen shrub or columnar tree [78,136]. Throughout most of North America, common juniper most often grows as a low, decumbent mat-forming shrub reaching up to 4.9 feet (1.5 m) in height and 7.6 to 13.1 feet (2-4 m) across [47,123]. In parts of New England common juniper occasionally grows up to 25 feet (7.6 m) in height, and a treelike growth form is reportedly common in Europe [78]. Height at maturity can range from 2 to 50 feet (0.6-15.3 m) [66]. At polar limits, common juniper grows as a dwarf shrub in forest tundra [65].
The bark of common juniper is thin, shreddy or scaly, often exfoliating into thin strips [56,123]. Twigs tend to be yellowish or green when young but turn brown and harden with age [47,123]. Leaves are simple, stiff and arranged in whorls of 3 [56,123]. Unlike most junipers, whose leaves turn scalelike at maturity, common juniper leaves remain needlelike throughout the shrub's life [88].
Male strobili are sessile or stalked, and female strobili are made up of green, ovate or acuminate scales [123]. Berrylike cones are red at first, ripening to a glaucous bluish-black [66].
Morphological characteristics including growth form differ somewhat according to variety. General botanical characteristics by variety are as follows [56,75,123,136]:
Juniperus communis var. depressa - rarely greater than 3 feet (1 m) tall
Juniperus communis var. montana A- low, trailing, mat-forming shrub, stems freely branched, usually less than 3 feet (0.9 m) tall
Individuals can live for more than 170 years [31].
Common juniper is possibly the most widely distributed tree in the world [78]. This circumboreal species occurs across North America, Europe, northern Asia and Japan [78,88]. Common juniper is almost completely circumpolar within the exception of a gap in the Bering Sea region [65]. It is widespread in North America beyond the northern limit of trees, occurring from western Alaska and British Columbia to Newfoundland, Greenland, and Iceland [78,88]. Common juniper extends southward through New England to the Carolinas and westward through northeastern Illinois, Indiana, northern Ohio, Minnesota, and Nebraska to the western mountains of Washington, California, Arizona, and New Mexico [47,56,78,88].
Distribution of common juniper in North America. 1971 USDA, Forest Service map digitized by Thompson and others [141].Distribution of North American varieties is as follows [47,56,78,88,136,63]:
Juniperus communis var. depressa northeastern North America, Idaho, Montana, the Great Plains, and Great Basin; found up to the low arctic in eastern North America
Juniperus communis var. montana high-northern latitudes, circumboreal [45]
In a north-central Colorado study of fire behavior in quaking aspen stands, common juniper patches burned more intensely and released more heat than adjacent herbaceous areas. A caloric analysis of 5 foliage samples yielded an average low heat content of 5064 kcal/kg. Common juniper fuels tended to be deeper and heavier than herbaceous fuels and flames were longer and deeper in common juniper patches. Fire removed almost all litter, standing herbs, and common juniper foliage, leaving only bare branches. The moisture of green common juniper foliage averaged 112% of oven dry weight on 2 burns [117]. Fuel loading for common juniper can be estimated as follows: branch load (kg/m2) = .000191* crown height above duff (cm) ** 2.135 foliage load (kg) = 6.456* crown volume (m3) ** 1.93 In xeric red pine (Pinus resinosa) communities of northern Canada, an understory of low sweet blueberry (Vaccinium angustifolium), lichen, and common juniper creates a low and discontinuous fuel load. Fires in these communities tend to have an irregular pattern of intensity that is largely dependent on the distribution of fine fuels. Intense crown fires are unlikely here [11].
Common juniper can grow on a wide range of sites. It grows on dry, open, rocky, wooded hillsides, sand terraces, maritime escarpments, and on exposed slopes and plateaus throughout its range [18,31,47,50,123]. Common juniper grows along dunes or on dune heath in coastal areas of the Northeast and inland along the Great Lakes [23,101]. It has spread into abandoned fields and pastures in New England [101] and the upper Midwest during the past century. In the southeast it is found on isolated mountains [2].
This species grows on a variety of soil types including acidic and calcareous sands, loams, or marls [9]. It is tolerant of ultramafic soils [85]. In much of Europe common juniper is restricted to well-aerated soils somewhat deficient in both nitrogen and phosphorus. Growth on different soil types is rated as follows [32]:
gravel: fair to poor organics: fair to poor sand: fair to good acidic: fair sandy-loam: good saline: fair to poor loam: good sodic: poor clay loam: fair to poor sodic-saline: poor clay: fair to poor dense clay: poor The following elevational ranges have been reported for common juniper [54,136]:
1 Jack pine
12 Black spruce
13 Black spruce-tamarack
14 Northern pin oak
15 Red pine
16 Aspen
18 Paper birch
19 Gray birch-red maple
35 Paper birch-red spruce-balsam fir
45 Pitch pine
107 White spruce
109 Hawthorn
110 Black oak
111 South Florida slash pine
201 White spruce
202 White spruce-paper birch
204 Black spruce
206 Engelmann spruce-subalpine fir
208 Whitebark pine
209 Bristlecone pine
210 Interior Douglas-fir
211 White fir
216 Blue spruce
217 Aspen
218 Lodgepole pine
219 Limber pine
220 Rocky Mountain juniper
229 Pacific Douglas-fir
230 Douglas-fir-western hemlock
237 Interior ponderosa pine
239 Pinyon-juniper
243 Sierra Nevada mixed conifer
244 Pacific ponderosa pine-Douglas-fir
245 Pacific ponderosa pine
248 Knobcone pine
249 Canyon live oak
251 White spruce-aspen
252 Paper birch
253 Black spruce-white spruce
254 Black spruce-paper birch
256 California mixed subalpine
FRES11 Spruce-fir
FRES15 Oak-hickory
FRES17 Elm-ash-cottonwood
FRES19 Aspen-birch
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES23 Fir-spruce
FRES26 Lodgepole pine
FRES28 Western hardwoods
FRES29 Sagebrush
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES35 Pinyon-juniper
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES44 Alpine
K001 Spruce-cedar-hemlock forest
K002 Cedar-hemlock-Douglas-fir forest
K005 Mixed conifer forest
K008 Lodgepole pine-subalpine forest
K011 Western ponderosa forest
K012 Douglas-fir forest
K013 Cedar-hemlock-pine forest
K015 Western spruce-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K020 Spruce-fir-Douglas-fir forest
K021 Southwestern spruce-fir forest
K022 Great Basin pine forest
K023 Juniper-pinyon woodland
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K040 Saltbush-greasewood
K052 Alpine meadows and barren
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K063 Foothills prairie
K064 Grama-needlegrass-wheatgrass
K065 Grama-buffalograss
K066 Wheatgrass-needlegrass
K067 Wheatgrass-bluestem-needlegrass
K081 Oak savanna
K093 Great Lakes spruce-fir forest
K095 Great Lakes pine forest
K096 Northeastern spruce-fir forest
K097 Southeastern spruce-fir forest
K098 Northern floodplain forest
K110 Northeastern oak-pine forest
109 Ponderosa pine shrubland
110 Ponderosa pine-grassland
216 Montane meadows
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
401 Basin big sagebrush
410 Alpine rangeland
411 Aspen woodland
902 Alpine herb
904 Black spruce-lichen
907 Dryas
912 Low scrub shrub birch-ericaceous
916 Sedge-shrub tundra
920 White spruce-paper birch
Common juniper is generally killed or seriously damaged by fire [24,25]. Patchy fires may allow individual plants to survive in protected areas such as on rocky cliffs. More rarely, portions of a lightly-burned plant may survive. The amount of damage this species incurs increases with increasing fire severity [120].
In the boreal forest of Quebec, at least 37% of common junipers survived fire. Although the dominant fire regime here is crown fires or "important surface fires covering large areas," common juniper often survives on sites made up of exposed bedrock or where protected by lakes and island complexes. Survival can occur if fire affects only part of an area or where fires are of low intensity. In some cases, fires of low intensity "can allow sections of the plant to survive and reproduce vegetatively" [31].
Wild ungulates generally eat only trace amounts of common juniper. Deer and mountain goats browse common juniper to at least a limited extent in some areas including Wyoming and Montana [10,35,41,43,55,93,95,111,134]. Levels of use are typically greatest during the winter or early spring. Common juniper can be important winter mule deer food during some years in parts of the Black Hills [29,43,95,99]. It is also used consistently through the winter months by white-tailed deer in the Swan Valley of Montana [92,93]. Caribou have been observed feeding on common juniper after fire [12]. Moose feed on common juniper "sparingly" in northern Michigan [94]. It also receives some light summer use by mountain goats in Montana [111]. In northern Canada, barren-ground caribou browse "fairly often" on common juniper where lichen growth is poor [69]. Hares browse common juniper in parts of Ontario where use may range from low to high [26].
Domestic livestock rarely utilize common juniper. The foliage may be poisonous to domestic goats, although livestock in parts of Europe have reportedly been fed sprays of common juniper with no ill effects [131].
Cones of most junipers are eaten by many species of birds and mammals. Numerous animals, including the American robin and black-capped chickadee, feed on the cones of common juniper whenever they are available. American robins frequently consume large numbers of cones during the spring and fall [101]. In eastern Ontario, cones provide food for cedar and Bohemian waxwings [20]. Wild turkeys also feed on cones of common juniper [27].
Common juniper is an indicator in a number of forest and
shrubland habitat types and community types. It grows as an
understory dominant with ponderosa pine (Pinus ponderosa),
Douglas-fir (Pseudotsuga menziesii), lodgepole pine
(Pinus contorta), limber pine (P. flexilis),
white fir (Abies concolor), Engelmann spruce (Picea engelmannii),
white spruce (P. glauca), quaking aspen (Populus tremuloides),
blue spruce (Picea pungens), whitebark pine (Pinus albicaulis),
subalpine fir (A. lasiocarpa), or Rocky Mountain bristlecone pine (P. aristata).
Common associates in northern Utah include common snowberry
(Symphoricarpos albus), gooseberry currant
(Ribes montigenum), Oregon-grape (Mahonia repens),
hairy telegraphplant (Heterotheca villosa), timber
milkvetch (Astragalus miser), silvery
lupine (Lupinus argenteus), Thurber fescue
(Festuca thurberi), elk sedge (Carex geyeri), and
bottlebrush squirreltail
(Elymus elymoides) [84,90]. Common juniper is listed as a
codominant indicator species in the following classifications:
Old-growth forests of the Canadian Rocky Mountain national
parks [1]
Forest vegetation on National Forests in the Rocky Mountain and
Intermountain Regions: habitat and community types [4]
Forest vegetation of the Medicine Bow National Forest in southeastern
Wyoming: a habitat type classification [5]
Classification of the forest vegetation on the National Forests of
Arizona and New Mexico [6]
The vegetation of the Grand River/Cedar River, Sioux, and Ashland
Districts of the Custer National Forest: a habitat type
classification [49]
Preliminary forest habitat types of the Uinta Mountains, UT [51]
Forested plant associations of the Olympic National Forest
[52]
Forest vegetation of the Arapaho and Roosevelt National Forests in
central Colorado: a habitat type classification [53]
Forest vegetation of the Bighorn Mountains, Wyoming: a habitat type
classification [57]
Forest vegetation of the Routt National Forest in northwest
Colorado: a habitat type classification [58]
Forest vegetation of the Black Hills National Forest of South Dakota and
Wyoming: a habitat type classification [59]
Forest vegetation of the Gunnison and parts of the Uncompahgre
National Forests: a preliminary habitat type classification
[72]
Forest and woodland habitat types (plant associations) of
northern New Mexico and northern Arizona [74]
Field guide for forested plant associations of the Wenatchee
National Forest [76]
Coniferous forest habitat types of northern Utah [84]
Aspen community types of the Intermountain Region [89]
Aspen community types of Utah [90]
A forest habitat type classification of southern Arizona and its
relationship to forests of the Sierra Madre Occidental of
Mexico [91]
Forest habitat types of Montana [100]
Forest habitat types of central Idaho [122]
Coniferous forest habitat types of central and southern Utah [138]
Aspen community types on the Bridger-Teton National Forest in
western Wyoming [139]
Classification and gradient analysis of forest vegetation of
Cape Enrage, Bic Park, Quebec [140]
Common juniper generally appears to increase in response to grazing
[19,102]. Butler [19] observed highest relative common juniper
cover in stands heavily grazed by cattle in green ash (Fraxinus pennsylvanica) draws
of the North Dakota badlands as follows:
Common juniper is rated as poor in overall protein and energy
value [32]. Nutritional value of common juniper in South Dakota was
reported as follows [43]:
Oct. 1 Jan. 2 April 1 July 1
------ ------ ------- ------
Moisture (%) 50.27 43.48 43.81 66.13
Carotene (?g/g) 56.63 16.30 52.08 57.88
Ash (%) 1.41 1.65 2.00 1.38
Crude fat (%) 6.07 7.51 7.16 4.12
Crude fiber (%) 11.28 15.50 12.70 9.51
Crude protein (%) 4.22 3.30 2.85 3.53
N-free extract (%) 26.75 28.56 31.49 15.35
Phosphorus (%) 0.087 0.081 0.12 0.07
Calcium (%) 0.36 0.85 0.67 0.25
Iron (ppm)* 94.97 91.02 92.68 40.49
Manganese (ppm)* 43.62 58.82 80.19 45.98
*parts per million
Foliar nutrient levels are as follows [15]:
Common juniper was used by Native Americans of the Great Basin as a blood tonic [88]. Native Americans from the Pacific Northwest used tonics made from the branches to treat colds, flu, arthritis, muscle aches, and kidney problems [130]. Cones were used by the southern Kwakiutl of British Columbia for treating stomach ailments and wood or bark was used to treat respiratory problems [129]. The Interior Salish used cones to make medicines for a variety of ailments [130]. Eurasians made tonics from common juniper for kidney and stomach ailments, and rheumatism [88,130]. Common juniper contains a volatile oil, terpinen-4-ol, which is known to increase kidney action [130]. Common juniper extract, which can be fatal in even fairly small amounts, was used to make gin and as a meat preservative [88].
Common juniper is highly valued as an ornamental [44]. It is widely cultivated and provides good ground cover even on stony or sandy sites [7,48,101]. This species was first cultivated in 1560 [66].
The palatability of common juniper to livestock and wildlife
species in several western states has been rated as follows
[32,55]: CO MT ND SD UT WY
Cattle poor poor poor ---- poor poor
Sheep poor poor poor ---- poor poor
Horses poor poor poor ---- poor poor
Pronghorn ---- ---- poor ---- poor poor
Elk ---- poor ---- ---- fair poor
Mule deer poor fair fair ---- fair good
White-tailed deer ---- poor poor low-med ---- fair
Small mammals ---- ---- fair ---- good good
Small nongame birds---- ---- good ---- good poor
Upland game birds ---- ---- good ---- good fair
Waterfowl ---- ---- ---- ---- poor good
Common juniper begins leader elongation in the spring. "Flowering" or cone development dates vary somewhat according to geographic location, but cone development generally occurs from April through June [47,56,66]. Generalized cone development dates by state are as follows [32]: State Beginning End of cone cone development development Montana April May North Dakota April May Wyoming April May Strobili form during June or July, and these structures fuse, generally during the 2nd year, to produce a berrylike cone [123]. Cones ripens from August through October of the 2nd or, more rarely, 3rd year. Cones generally remain on the plant for at least 2 years [66], with dispersal occurring in August of the second season [126]. In the Canadian subarctic, cones are initiated in autumn and open the following year when pollination occurs. Male strobili are shed while the female cones are enlarging and fertilization occurs during the 2nd year. Seeds mature during the 3rd year [63].
Common juniper does not sprout after disturbance. Surviving individuals serve as sources of seed for adjacent areas. Postfire regeneration is more frequent in proximity to existing populations of common junipers [31]. Regrowth can generally take place after fire if some of the basal branches remain alive [82], which only occurs in fires of low severity or where spread is patchy.
Common juniper also reestablishes after fire through off-site seed dispersed by birds or mammals. Poor seed dispersal from existing stands along with low germination rates can explain why some favorable sites are not readily occupied by common juniper [31].
It is possible that seed protected by overlying soil can survive at least some fires. After low-severity fires, some seed may germinate. However, Mallik and Gimingham [82] observed that high temperatures did not increase germination in common juniper seed and little seed germinated after fire.
Common juniper is typically dioecious but occasionally monoecious [128]. Seed usually matures during the second growing season [56,123,126,136], although there have been some reports of cones maturing within only one season [128].
Common juniper produces large cone crops at irregular intervals [66]. Cones are ovoid to ellipsoid [123] and contain 1 to 3 seeds [56,128]. Germination rates for common juniper seed are relatively poor and defective seed may also be relatively common. Pack [97] reported that up to 60% of common juniper seeds examined were defective. In northwestern Quebec, the majority of seeds produced by "older" plants (94.8%) were non-viable. A majority of seeds produced by "younger" plants (80%) were viable. Approximately 40 to 60% of "older" plants were sterile [31]. Under harsh conditions, female plants may decrease reproductive efforts and less viable seed is produced [83].
Germination and seedling establishment of common juniper is "difficult" [31,60]. Ideal germination conditions are moist, compact soil with sufficient oxygen diffusion [31]. Germination has been reported to range from 7 to 75%, depending on the specific treatment and seed source [66].
Juniper seeds have a semipermeable and thick seedcoat with a dormant embryo [97]. Common juniper seed requires a period of warm temperatures followed by a period of cold temperatures lasting approximately 7 months [31]. Generally the germination rate of seeds that are not afterripened is only around 1% [97]. High temperatures, alternating temperatures, freezing and thawing, removal of the seedcoat, or the application of hydrogen peroxide, dilute acids, carbon dioxide, or light had little influence on the germination of juniper seeds.
Steele and Geier-Hayes [121] report that common juniper seed is dispersed by animals and not stored in the soil. However, Major and Pyott [80] report that common juniper seed persists in cropped soils in California. Seeds of common juniper are dispersed by gravity, water, birds, or mammals. Digestive processes apparently do not harm most juniper seeds and may actually enhance germination [8,37]. Birds are the most important dispersal agents of common juniper [31]. More than 60 to 85% of common junipers present in the sand dune region surrounding Lake Michigan are believed to have originated from bird-disseminated seed. Birds also contribute to the spread of common juniper into old fields of New England [101]. Rosen [109] reports that domestic sheep may also serve as a dispersal agent since junipers are often associated with sheep driveways. Strong winter winds can push seeds across frozen snow cover [109].
Increases observed in seedling numbers during certain periods are the result of favorable conditions for establishment. Establishment is more likely in open spaces between older shrubs and may be favored by grazing [109].
Common juniper does not sprout after foliage is removed. However, adventitious root development can occur when branches come in contact with the ground become buried. In the subarctic, plants are often buried at least partially, and production of adventitious roots may aid in water and nutrient intake. A higher proportion of common juniper cuttings from northern populations rooted as compared with southern cuttings. Cuttings from female shrubs may exhibit better rooting potential than cuttings from male plants [63].
1 Northern Pacific Border
2 Cascade Mountains
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands
Common juniper is intolerant of shade and is usually found in open environments [31]. Common juniper is often regarded as a colonizing plant but reaches maximum abundance on harsh, stressed environments in which competition is lacking [31,107]. Common juniper occurs as an important understory species in a number of climax communities within the southern Rocky Mountains including some Douglas-fir, subalpine fir, limber pine, Engelmann spruce, and blue spruce stands [6,91,122]. Common juniper becomes prominent in many high-elevation spruce-fir forests in Colorado as much as 100 years or more after fire or other disturbance [21]. In the boreal forest of eastern Canada, however, common juniper begins to decline after approximately 70 years after disturbance. On harsh open sites, it can persist for much longer which creates patchy habitats [31].
Common juniper is described as a seral species in common juniper/bearberry (Arctostaphylos uva-ursi) communities of the southwestern Yukon where it is ultimately replaced by spruce (Picea spp.) and buffaloberry (Shepherdia canadensis) [34]. In Arizona and Colorado, common juniper is prominent in seral stands with Oregon-grape [36] and in the northern Rocky Mountains, it occurs in late seral stands in Douglas-fir/ninebark (Physocarpos malvaceus) and Douglas-fir/Rocky Mountain maple (Acer glabrum) habitat types [121]. It is prominent in old-field or "early settlement" communities of New England, but it "disappears" from areas maintained in timber [39,40]. In pitch pine (Pinus rigida) communities of New England, common juniper replaces initial colonizers such as lichens, blueberries (Vaccinium spp.), and grasses, and is in turn, replaced later in succession by pitch pine [87]. In black spruce communities of northern Saskatchewan, common juniper is most prevalent in secondary successional stages occurring from 11 to 30 years after disturbance [113]. In Michigan, common juniper is a colonizer on dune blowouts [96].
The currently accepted scientific name of common juniper is
Juniperus communis L. (Cupressaceae)
[45,47,54,67,132,135,136,]. A number of varieties
have been described. Commonly recognized North American
varieties include:
Juniperus communis var. communis
Juniperus communis var. charlottensis R.P. Adams [132]
Juniperus communis var. depressa Pursh [33,47,67,103,132,136,137]
Juniperus communis var. megistocarpa Fern & St. John [67,108,132]
Juniperus communis var. montana Ait. [67,132]
Common juniper has low value for short-term rehabilitation projects but moderate to high value for long-term rehabilitation projects. It is useful in preventing soil erosion [32]. Houle and Babeux [63] report that common juniper has potential for restoration in the Canadian arctic and subarctic.
Dietz and others [30] attempted to reestablish common juniper on old burns and on open ponderosa pine sites in the Black Hills. Best results were obtained with bareroot stock planted during late April. Attempts at hand seeding under greenhouse conditions were largely unsuccessful.
The wood of common juniper is fine grained, durable, and reddish with white sapwood [123]. This wood currently has no commercial value.
USA: AL , AK , AZ , CA , CO , CT , DE , GA , ID , IL , IN , IA , KY , ME , MD , MA , MI , MN , MT , NE , NV , NH , NJ , NM , NY , NC , ND , OH , OR , PA , RI , SC , SD , UT , VT , VA , WA , WV , WI , WY (NPIN, 2007)
Canada: AB , BC , MB , NB , NL , NS , ON , PE , QC , SK (NPIN, 2007)
Native Distribution: Widespread from Alaska east to Labrador and S. Greenland, south to New York, and west to Minnesota and Wyoming; also south in mountains to NW. South Carolina and central Arizona; also Iceland and across N. Eurasia; to 8000-11,5000 (2438-3505 m) in south. (NPIN, 2007)
Native: (USDA GRIN, 2007)
AFRICA
Northern Africa: Algeria [n.]; Morocco
ASIA-TEMPERATE
Western Asia: Afghanistan; Turkey
Caucasus: Azerbaijan; Georgia; Russian Federation - Dagestan
Siberia: Russian Federation - Eastern Siberia, Western Siberia
Soviet Middle Asia: Kazakhstan [e.]; Kyrgyzstan; Tajikistan
Soviet Far East: Russian Federation - Kamchatka, Kurile Islands, Sakhalin
China: China - Jilin, Xinjiang, Xizang
Eastern Asia: Japan - Hokkaido, Honshu; Korea
ASIA-TROPICAL
Indian Subcontinent: Nepal; Pakistan
EUROPE
Northern Europe: Denmark; Finland; Ireland; Norway; Sweden; United Kingdom
Middle Europe: Austria; Belgium; Germany; Hungary; Netherlands; Poland; Switzerland
East Europe: Belarus; Estonia; Latvia; Lithuania; Moldova; Russian Federation - European part; Ukraine [incl. Krym]
Southeastern Europe: Albania; Bulgaria; Former Yugoslavia; Greece;
Italy [incl. Sardinia, Sicily]; Romania
Southwestern Europe: France [incl. Corsica]; Portugal; Spain
NORTHERN AMERICA
Subarctic America: Canada - Northwest Territory, Yukon Territory;
United States - Alaska
Eastern Canada: Canada - New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec
Western Canada: Canada - Alberta, British Columbia, Manitoba, Saskatchewan
Northeastern U.S.A.: United States - Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New York, Ohio, Pennsylvania, Rhode Island, Vermont
North-Central U.S.A.: United States - Illinois [n. & e.], Minnesota, North Dakota, South Dakota [n.w.], Wisconsin
Northwestern U.S.A.: United States - Colorado, Idaho, Montana, Oregon, Washington, Wyoming
Southeastern U.S.A.: United States - Georgia [n.], North Carolina, South Carolina, Virginia
South-Central U.S.A.: United States - New Mexico
Southwestern U.S.A.: United States - Arizona, California, Nevada, Utah
Flowers Flowers are yellow. (USDA PLANTS, 2009) Juniper is dioecious (separate male and female plants). (FNA, 2004)
Fruit Fruit color is blue. (USDA PLANTS, 2009) Berries are subglobose. (Peattie, 1930) Seed cones/fruit are two distinct sizes. The fruit have straight peduncles. Fruit are globose to ovoid, bluish black, glaucous (having a whitish waxy outer layer), and resinous to obscurely woody. Fruit bear 2-3 seeds. (FNA, 2004)
Leaves Foliage color is green. Foliage is dense year-round. (USDA PLANTS, 2009) Foliage consists of prickly needles. (Weatherbee, 2006) Leaves are thin and straight. Leaves occur in whorls of 3 and are widely spreading. Leaves are free and jointed at base, prickly-pointed, and linear-subulate. They are channeled and whitened above, and grayish beneath. (Peattie, 2009) Leaves are green, but sometimes appearing silver when glaucous. They are spreading. Abaxial (away from leaf axis) glands are very elongate. Adaxial surface (toward stem) bears a glaucous stomatal band. Leaf apex can be acute to obtuse and is mucronate (abruptly projecting point). (FNA, 2004)
Stems Branches are erect and arching. (Weatherbee, 2006) It is multistemmed. Branches can be spreading or ascending. Branchlets are erect and terete (cylindrical or slightly tapering). (FNA, 2004)
Bark is brown, fibrous, and exfoliates in thin strips. That of small branchlets is smooth, while that of larger branchlets exfoliates in strips and plates. (FNA, 2004)
Plant Maximum height at 20 years is 5'. Height at maturity is 10.0'. (USDA PLANTS, 2009) It is 2-4 m tall. (Peattie, 1930) May grow to 4 m in shrub form, if trees to 10 m. (FNA, 2004)
Fruit is a berry 6-8 mm thick. (Peattie, 1930) Seed cones are 6-13 mm. Seeds are 4-5 mm. (FNA, 2004)
Leaves are 12-21 mm long x 1.5 mm broad at the base. (Peattie, 1930)
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 10 metres (33 feet)—rarely 16 m (52 ft)—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.[2]: 55 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.[3][4][5][6]
The male cones are yellow, 2–3 millimetres (3⁄32–1⁄8 in) 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, 4–12 mm (5⁄32–15⁄32 in) 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.[7][8][9]
Young shoots, Malá Fatra
Male cones
Ripe and unripe juniper berries in Saaremaa, Estonia
Close-up of foliage and cones
J. communis subsp. communis on Lüneburg Heath, Germany
The juniper berry oil is composed largely of monoterpene hydrocarbons such as α-pinene, myrcene, sabinene, limonene and β-pinene.[10]
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.[7][8][9][11][12][13][14]
Some botanists treat subsp. alpina at the lower rank of variety, in which case the correct name is J. communis var. saxatilis Pallas,[8] though the name J. communis var. montana is also occasionally cited; others, primarily in eastern Europe and Russia, sometimes treat it as a distinct species J. sibirica Burgsd. (syn. J. nana Willd., J. alpina S.F.Gray).[15]
The species has the largest geographical range of any woody plant, with a circumpolar distribution throughout the cool temperate Northern Hemisphere from the Arctic south in mountains to around 30°N latitude in North America, Europe and Asia.[16] Relict populations can be found in the Atlas Mountains of Africa.[16]
J. communis is one of Ireland's longest established plants.[17]
Juniperus communis is cultivated in the horticulture trade and used as an evergreen ornamental shrub in gardens. The following cultivars gained the Royal Horticultural Society's Award of Garden Merit in 1993:[18]
It is too small to have any general lumber usage. In Scandinavia, however, juniper wood is used for making containers for storing small quantities of dairy products such as butter and cheese, and also for making wooden butter knives. It was also frequently used for trenails in wooden shipbuilding by shipwrights for its tough properties.
In Estonia juniper wood is valued for its long lasting and pleasant aroma, very decorative natural structure of wood (growth rings) as well as good physical properties of wood due to slow growth rate of juniper and resulting dense and strong wood. Various decorative items (often eating utensils) are common in most Estonian handicraft shops and households.
According to the old tradition, on Easter Monday Kashubian (Northern Poland) boys chase girls whipping their legs gently with juniper twigs. This is to bring good fortune in love to the chased girls.
Juniper wood, especially burl wood, is frequently used to make knife handles for French pocketknives such as the Laguiole.
Its astringent blue-black seed cones, commonly known as juniper berries, are too bitter to eat raw and are usually sold dried and used to flavour meats, sauces, and stuffings. They are generally crushed before use to release their flavour. Since juniper berries have a strong taste, they should be used sparingly. They are generally used to enhance meat with a strong flavour, such as game, including game birds, or tongue.
The cones are used to flavour certain beers and gin (the word "gin" derives from an Old French word meaning "juniper").[23] In Finland, juniper is used as a key ingredient in making sahti, a traditional Finnish ale. Also the Slovak alcoholic beverage Borovička and Dutch Jenever are flavoured with juniper berry or its extract.
Juniper is used in the traditional farmhouse ales of Norway,[24] Sweden,[25] Finland,[26] Estonia, and Latvia. In Norway, the beer is brewed with juniper infusion instead of water, while in the other countries the juniper twigs are mainly used as filters to prevent the crushed malts from clogging the outlet of the lauter tun. The use of juniper in farmhouse brewing has been common in much of northern Europe, seemingly for a very long time.[27]
Juniper berries have long been used as medicine by many cultures including the Navajo people.[28] Western American tribes combined the berries of J. communis with Berberis root bark in a herbal tea. Native Americans also used juniper berries as a female contraceptive.[29]
Juniper leaves were found to harbor fungi with potent anti-fungal compounds,[30] including ibrexafungerp, which is now FDA approved to treat fungal infections.
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.
