Juniper

Juniperus
Juniperus osteosperma in Nevada
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Cupressaceae
Genus: Juniperus
L.
Species

See text

Junipers are coniferous plants in the genus Juniperus (pronounced /dʒuːˈnɪpərəs/)[1] of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the mountains of Central America.

Contents

Description

Cones and leaves of Juniperus communis

Junipers vary in size and shape from tall 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 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 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 long; and the leaves on mature plants are (mostly) tiny (2-4 mm long), 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.

Juniper is the exclusive food plant of the larvae of some Lepidoptera species including Bucculatrix inusitata and Juniper Carpet, and is also eaten by the larvae of other Lepidoptera species such as Chionodes electella, Chionodes viduella, Juniper Pug and Pine Beauty; those of the tortrix moth C. duplicana feed on the bark around injuries or canker.

Classification

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.

Juniper needles, magnified. Left, Juniperus communis (Juniperus sect. Juniperus; note needles 'jointed' at base). Right, Juniperus chinensis (Juniperus sect. Sabina; note needles merging smoothly with the stem, not jointed at base).
Juniperus phoenicea on El Hierro, Canary Islands
An Eastern Juniper in October laden with ripe cones.
Cones and seeds.
Juniperus occidentalis var. australis, eastern Sierra Nevada, Rock Creek Canyon, California.

Cultivation and uses

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 juniper trees are misleadingly given the common name "cedar," including Juniperus virginiana, the "red cedar" that is used widely in cedar drawers. True cedars are those tree species in the genus Cedrus, family Pinaceae.

In Morocco, the sandarac resin (القطران) of the arar tree (العَرعَر) is applied in dotted patterns onto bisque drinking cups. Sandarac makes the water more fragrant and is said to be good for the teeth.

Native Americans have used juniper to treat diabetes; such treatments by the Navajo, for example, are under clinical study.[3] Clinical studies have shown that treatment with juniper may retard the development of streptozotocin diabetes in mice.[4] Native Americans also used juniper berries as a female contraceptive.[5] The 17th Century herbalist physician Nicholas Culpeper recommended the ripened berries for conditions such as asthma and sciatica, as well as to speed childbirth.[6]

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.

References

  1. Sunset Western Garden Book, 1995:606–607
  2. Adams, Robert. "Phytologia (April 2010) 92(1)". http://www.juniperus.org/AdamsPapersPDFFiles/238-92%281%29105-117AdamsJzanoniiCerroPotosiandFcompataIxta.pdf. 
  3. .; McCabe, M.D., Melvina; Gohdes, M.D., Dorothy; Morgan, B.S., Frank; Eakin, M.A., Joanne; Sanders, Ph.D., Margaret; Schmitt, M.S., Cheryl (2005), "Herbal Therapies and Diabetes Among Navajo Indians", Diabetes Care 28 (6): 1534–1535, doi:10.2337/diacare.28.6.1534-a, http://care.diabetesjournals.org/content/28/6/1534.2.full, retrieved 2009-12-28 
  4. 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, http://www.springerlink.com/content/jm20vr2438103g84/, retrieved 2009-12-28 
  5. Edible and Medicinal Plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1
  6. Culpeper's Complete Herbal, Nicholas Culpeper, ISBN 1-85007-026-1

External links