Junipers are coniferous plants

in the genus Juniperus 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 in the New World.

Juniperus
Juniperus communis shrubs in The Netherlands
Scientific classification
Kingdom: Plantae Division: Pinophyta Class: Pinopsida Order: Pinales Family: Cupressaceae Genus: Juniperus L.
Species
50-55 species; see text.

Junipers vary in size and shape from tall trees to 20-40 m tall, to columnar or low spreading shrubs with long trailing branches. They are evergreen with either 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 (for their use as a spice, see Juniperus communis). 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 being 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.

Classification

The number of juniper species is disputed, 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 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 communis - Common Juniper
Juniperus communis subsp. alpina - Alpine Juniper
Juniperus conferta - Shore Juniper (syn. J. rigida var. conferta)
Juniperus rigida - Temple Juniper or Needle Juniper
Juniperus sect. Juniperus subsect. Oxycedrus: Cones with 3 separate seeds; needles with two stomatal bands.
Juniperus brevifolia - Azores Juniper
Juniperus cedrus - Canary Islands Juniper
Juniperus deltoides - Eastern Prickly Juniper
Juniperus formosana - Chinese Prickly Juniper
Juniperus luchuensis - Ryukyu Juniper
Juniperus navicularis - Portuguese Prickly Juniper
Juniperus oxycedrus - Western Prickly Juniper or Cade Juniper
Juniperus macrocarpa (J. oxycedrus subsp. macrocarpa) - Large-berry Juniper
Juniperus sect. Juniperus subsect. Caryocedrus: Cones with 3 seeds fused together; needles with two stomatal bands.
Juniperus drupacea - Syrian Juniper

Provisionally, all the other junipers are included here, though they form a paraphyletic group.

Juniperus angosturana - Mexican One-seed Juniper
Juniperus ashei - Ashe Juniper
Juniperus barbadensis - West Indies Juniper
Juniperus bermudiana - Bermuda Juniper
Juniperus blancoi - Blanco’s Juniper
Juniperus californica - California Juniper
Juniperus chinensis - Chinese Juniper
Juniperus chinensis var. sargentii - Sargent’s Juniper
Juniperus coahuilensis - Coahuila Juniper
Juniperus comitana - Comitán Juniper
Juniperus convallium - Mekong Juniper
Juniperus deppeana - Alligator Juniper
Juniperus durangensis - Durango Juniper
Juniperus excelsa - Greek Juniper
Juniperus excelsa subsp. polycarpos - Persian Juniper
Juniperus flaccida - Mexican Weeping Juniper
Juniperus foetidissima - Stinking Juniper
Juniperus gamboana - Gamboa Juniper
Juniperus gaussenii - Gaussen’s Juniper
Juniperus horizontalis - Creeping Juniper
Juniperus indica - Black Juniper
Juniperus jaliscana - Jalisco Juniper
Juniperus komarovii - Komarov’s Juniper
Juniperus monosperma - One-seed Juniper
Juniperus monticola - Mountain Juniper
Juniperus occidentalis - Western Juniper
Juniperus occidentalis subsp. australis - Sierra Juniper
Juniperus osteosperma - Utah Juniper
Juniperus phoenicea - Phoenicean Juniper
Juniperus pinchotii - Pinchot Juniper
Juniperus procera - East African Juniper
Juniperus procumbens - Ibuki Juniper
Juniperus pseudosabina - Xinjiang Juniper
Juniperus recurva - Himalayan Juniper
Juniperus recurva var. coxii - Cox’s Juniper
Juniperus sabina - Savin Juniper
Juniperus sabina var. davurica - Daurian Juniper
Juniperus saltillensis - Saltillo Juniper
Juniperus saltuaria - Sichuan Juniper
Juniperus scopulorum - Rocky Mountain Juniper
Juniperus semiglobosa - Russian Juniper
Juniperus squamata - Flaky Juniper
Juniperus standleyi - Standley’s Juniper
Juniperus thurifera - Spanish Juniper
Juniperus tibetica - Tibetan Juniper
Juniperus virginiana - Eastern Juniper
Juniperus virginiana subsp. silicicola - Southern Juniper
Juniperus wallichiana - Himalayan Black Juniper

Additional notes

Some junipers are susceptible to Gymnosporangium rust disease, and can be a serious problem for those growing Apples, the alternate host of the disease.

The Rocky Mountain Juniper (J. scopulorum), One-seed Juniper (J. monosperma), Western Juniper (J. occidentalis), Utah Juniper (J. osteosperma) and California Juniper (J. californica) occur in the western United States. In the southwest United States there are four more species, including the Alligator Juniper (J. deppeana) with its thick bark checkered into scaly squares.

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 East Asia) are extensively used in landscaping and horticulture, it is also a symbol of longevity.

Juniper berries are used in the distillation of gin and the brewing of sahti.

Some junipers are sometimes misleadingly called cedars, correctly the vernacular name for species in the genus Cedrus, family Pinaceae.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article “Juniper”.

This entry was posted on Friday, October 28th, 2005 at 9:56 am and is filed under Aromatherapy and Essential Oils. Both comments and pings are currently closed.