Junipers vary in size and shape from tall trees, 20–40 m (66–131 ft) tall, to columnar or low spreading shrubs with long trailing branches. They are evergreen with needle-like and/or scale-like leaves. They can be either monoecious or dioecious. The female seed cones are very distinctive, with fleshy, fruit-like coalescing scales which fuse together to form a "berry"-like structure, 4–27 mm (0.16–1.06 in) long, with 1–12 unwinged, hard-shelled seeds. In some species these "berries" are red-brown or orange but in most they are blue; they are often aromatic and can be used as a spice. The seed maturation time varies between species from 6–18 months after pollination. The male cones are similar to those of other Cupressaceae, with 6–20 scales; most shed their pollen in early spring, but some species pollinate in the autumn.
Detail of Juniperus chinensis shoots, with juvenile (needle-like) leaves (left), and adult scale leaves and immature male cones (right)
Many junipers (e.g. J. chinensis, J. virginiana) have two types of leaves: seedlings and some twigs of older trees have needle-like leaves 5–25 mm (0.20–0.98 in) long; and the leaves on mature plants are (mostly) tiny (2–4 mm (0.079–0.157 in)), overlapping and scale-like. When juvenile foliage occurs on mature plants, it is most often found on shaded shoots, with adult foliage in full sunlight. Leaves on fast-growing 'whip' shoots are often intermediate between juvenile and adult.
In some species (e. g. J. communis, J. squamata), all the foliage is of the juvenile needle-like type, with no scale leaves. In some of these (e.g. J. communis), the needles are jointed at the base, in others (e.g. J. squamata), the needles merge smoothly with the stem, not jointed.
The needle-leaves of junipers are hard and sharp, making the juvenile foliage very prickly to handle. This can be a valuable identification feature in seedlings, as the otherwise very similar juvenile foliage of cypresses (Cupressus, Chamaecyparis) and other related genera is soft and not prickly.
The number of juniper species is in dispute, with two recent studies giving very different totals, Farjon (2001) accepting 52 species, and Adams (2004) accepting 67 species. The junipers are divided into several sections, though (particularly among the scale-leaved species) which species belong to which sections is still far from clear, with research still on-going. The section Juniperus is an obvious monophyletic group though.
Juniperus sect. Juniperus: Needle-leaf junipers. The adult leaves are needle-like, in whorls of three, and jointed at the base (see below right).
Juniperus sect. Juniperus subsect. Juniperus: Cones with 3 separate seeds; needles with one stomatal band.
Juniperus sect. Sabina: Scale-leaf junipers. The adult leaves are mostly scale-like, similar to those of Cupressus species, in opposite pairs or whorls of three, and the juvenile needle-like leaves are not jointed at the base (including in the few that have only needle-like leaves; see below right). Provisionally, all the other junipers are included here, though they form a paraphyletic group.
Juniper (Juniperus osteosperma and scopulorum) essential oil
Juniper berries are a spice used in a wide variety of culinary dishes and best known for the primary flavoring in gin (and responsible for gin's name, which is a shortening of the Dutch word for juniper, genever). Juniper berries are also used as the primary flavor in the liquor Jenever and sahti-style of beers. Juniper berry sauce is often a popular flavoring choice for quail, pheasant, veal, rabbit, venison and other meat dishes.
Many of the earliest prehistoric people lived in or near juniper forests which furnished them food, fuel, and wood for shelter or utensils. Many species, such as J. chinensis (Chinese Juniper) from eastern Asia, are extensively used in landscaping and horticulture, and as one of the most popular species for use in bonsai. It is also a symbol of longevity, strength, athleticism, and fertility.
Some junipers are susceptible to Gymnosporangium rust disease, and can be a serious problem for those people growing apple trees, the alternate host of the disease.
Some junipers are given the common name "cedar," including Juniperus virginiana, the "red cedar" that is used widely in cedar drawers. "Eastern redcedar" is the correct name for J. virginiana. The lack of space between the words "red" and "cedar" indicate that this species is not a true cedar, Cedrus.
In Morocco, the tar (gitran) of the arar tree (Juniperus phoenicea) is applied in dotted patterns on bisque drinking cups. Gitran makes the water more fragrant and is said to be good for the teeth.
Juniper berries are steam distilled to produce an essential oil that may vary from colorless to yellow or pale green. Some of its chemical components are alpha pinene, cadinene, camphene and terpineol. Leaves and twigs of Juniperus virginiana are steam distilled to produce oil of juniper. Middle Tennessee and adjacent northern Alabama and southern Kentucky are the centers for this activity. The U.S. Forest Service has provided plans for the apparatus required. This work is typically done during periods of cold weather to reduce the loss of essential oil to evaporation, which is greater in warmer weather, and to take advantage of a time of year when labor might be more readily available.
^McCabe, Melvina; Gohdes, Dorothy; Morgan, Frank; Eakin, Joanne; Sanders, Margaret; Schmitt, Cheryl (2005). "Herbal Therapies and Diabetes Among Navajo Indians". Diabetes Care 28 (6): 1534–1535. doi:10.2337/diacare.28.6.1534-a.|accessdate= requires |url= (help)
^Swanston-Flatt, S. K.; Day, C.; Bailey, C. J.; Flatt, P. R. (1990). "Traditional plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice". Diabetologia 33 (8): 462–464. doi:10.1007/BF00405106. PMID2210118.|accessdate= requires |url= (help)
^Tilford, Gregory L. (1997). Edible and Medicinal Plants of the West. Mountain Press Publishing Company. ISBN0-87842-359-1.
^Culpeper, Nicholas (1985). Culpeper's Complete Herbal. Godfrey Cave Associates. ISBN1-85007-026-1.
^McNeill, F. Marian (1961). "X Hogmany Rites and Superstitions". The Silver Bough, Vol.3: A Calendar of Scottish National Festivals, Halloween to Yule. Glasgow: William MacLellan. p. 113. ISBN0-948474-04-1.
^Loughlin, Annie "Saining" at Tairis UK. Accessed 8-6-14
Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4
Mao, K., Hao, G., Liu J., Adams, R. P. and R. I., Milne. (2010). Diversification and biogeography of Juniperus (Cupressaceae): variable diversification rates and multiple intercontinental dispersals. New Phytologist 188(1): 254-272.
Juniperus (the junipers) is a genus of 50–67 and 34 varieties species of evergreen coniferous trees and shrubs in the Cupressaceae (cypress family), widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the mountains of Central America, with one species (J. procera) in east Africa extending into the southern hemisphere. Juniperus is the second most diverse genus of conifers. Hundreds of horticultural cultivars have been developed for ornamental use worldwide, and the berry-like cones are used to flavor gin.
Junipers vary in size and shape from trees, 20–40 m tall, to columnar or low-spreading shrubs with long, trailing branches. They are evergreen with needle-like and/or scale-like leaves. They can be either monoecious (male and female flowers on the same plant) or dioecious (male and female flowers on separate plants). The female seed cones are very distinctive, with fleshy, fruit-like coalescing scales which fuse together to form a berry-like structure, 4–27 mm long, with 1-12 unwinged, hard-shelled seeds. In some species these "berries" are red-brown or orange but in most they are blue; they are often aromatic and can be used as a spice.
Juniper berries are used as a flavoring in diverse culinary dishes and best known for the primary flavoring in gin (and responsible for gin's name, which is a shortening of the Dutch word for juniper, genever). Juniper berry sauce is often a popular flavoring choice for quail, pheasant, veal, rabbit, venison and other meat dishes. The leaves and berries can also be used to make tea.
Many early prehistoric people lived in or near juniper forests which furnished them food, fuel, and wood for shelter or utensils. Some species are used extensively in landscaping and horticulture. For example, J. chinensis (Chinese juniper) from eastern Asia is a widely-planted ornamental and is as one of the most popular species used in bonsai. It is also a symbol of longevity, strength, athleticism, and fertility.
Junipers grow in habitats ranging from limestone outcrops to sand dunes, sandstone, and granite, but may also occur in bogs. Seed dispersal is generally by frugiverous birds, as passage through a bird gut helps break down the hard seed coat and promotes germination. In North America, junipers have become weedy and have invaded millions of acres of abandoned agricultural land; the present distribution is broader and extends farther north than it did prior to European settlement.
In many semiarid regions, including the western U.S., northern Mexico and central to southwest Asia, Juniper species form the dominant tree cover on large areas. J. communis, common juniper, is widely distributed throughout the northern hemisphere, and is the single most widespread conifer species.
Some juniper trees are misleadingly given the common name "cedar," including J. virginiana, the "eastern red-cedar" of North America, the aromatic wood of which is widely used to make moth-repelling cedar drawers, drawer liners, and shelving. However, true cedars are those tree species in the genus Cedrus, family Pinaceae.
(Adams 2008, Gymnosperm Database 2011, Wikipedia 2011)
Adams, R.P. 2008. Junipers of the World: The genus Juniperus. 2nd ed. Vancouver: Trafford Publishing Co. 402 p.
Evergreen shrubs or trees, dioecious or monoecious. Mature leaves decussate, appressed, imbricate and small; juvenile leaves subulate and spreading. Male cones of several scales bearing 2-6 pollen-sacs. Female cones fleshy, berry-like and indehiscent; scales fleshy, swollen and fused. Seeds 1-few.
Barcode of Life Data Systems (BOLD) Stats Specimen Records:413 Specimens with Sequences:549 Specimens with Barcodes:406 Species:84 Species With Barcodes:84 Public Records:278 Public Species:79 Public BINs:0