Juniperus virginiana — its common names include red cedar, eastern red-cedar,
eastern redcedar, eastern juniper, red juniper, pencil cedar, and aromatic
cedar — is a species of juniper native to eastern North America from
southeastern Canada to the Gulf of Mexico and east of the Great Plains.
Further west it is replaced by the related Juniperus scopulorum and to the
southwest by Juniperus ashei. Description
Juniperus virginiana is a dense slow-growing coniferous evergreen tree
that may never become more than a bush on poor soil, but is ordinarily from
5–20 m or 16–66 ft tall, with a short trunk 30–100 cm or 12–39 in diameter.
The oldest tree reported, from Missouri, was 795 years old. The bark is
reddish-brown, fibrous, and peels off in narrow strips. The leaves are of two
types; sharp, spreading needle-like juvenile leaves 5–10 cm long, and
tightly adpressed scale-like adult leaves 2–4 mm long; they are arranged in
opposite decussate pairs or occasionally whorls of three. The juvenile leaves are
found on young plants up to 3 years old, and as scattered shoots on adult trees,
usually in shade. The seed cones are 3–7 mm long, berry-like, dark purple-blue
with a white wax cover giving an overall sky-blue color; they contain one to
three seeds, and are mature in 6–8 months from pollination. The Juniper
berry is an important winter food for many birds, which disperse the wingless
seeds. The pollen cones are 2–3 mm long and 1.5 mm broad, shedding pollen in
late winter or early spring. The trees are usually dioecious, with pollen and
seed cones on separate trees. There are two varieties, which
intergrade where they meet: Juniperus virginiana var. virginiana is
called eastern juniper / redcedar. It is found in eastern North America, from
Maine, west to southern Ontario and South Dakota, south to northernmost
Florida and southwest into the post oak savannah of east-central Texas. Cones
are larger, 4–7 mm; scale leaves are acute at apex and bark is red-brown.
Juniperus virginiana var. silicicola E.Murray L.H.Bailey) is known as
southern or sand juniper / redcedar. Habitat is along the Atlantic and Gulf
coasts from North Carolina, south to central Florida and west to southeast
Texas. Cones are smaller, 3–4 mm; scale leaves are blunt at apex and the bark is
orange-brown. It is treated by some authors at the lower rank of variety,
while others treat it as a distinct species.
Ecology It is a pioneer invader, which means
that it is one of the first trees to repopulate cleared, eroded, or otherwise
damaged land. It is unusually long lived among pioneer species, with the
potential to live over 850 years. The tree is commonly found in prairies or
oak barrens, old pastures, or limestone hills, often along highways and near
recent construction sites. It is an alternate host for cedar-apple rust
disease, an economically significant disease of apples, and some management
strategies recommend the removal of J. virginiana near apple orchards
In many areas the trees are considered an invasive species, even if native. The
fire intolerant J. virginiana was previously controlled by periodic
wildfires. Low branches near the ground burn and provide a ladder that allows
fire to engulf the whole tree. Grasses recover quickly from low severity fires
that are characteristic of prairies that kept the trees at bay. With the
urbanization of prairies, the fires have been stopped with roads, plowed fields,
and other fire breaks, allowing J. virginiana and other trees to invade.
Trees are destructive to grasslands if left unchecked, and are actively being
eliminated by cutting and prescribed burning. The trees also burn very
readily, and dense populations were blamed for the rapid spread of wildfires
in drought stricken Oklahoma and Texas in 2005 and 2006.
Junipers also benefit from the increased CO2 levels, unlike the grasses with
which they compete. Many grasses are C4 plants that concentrate CO2 levels in
their bundle sheaths to increase the efficiency of RuBisCO, the enzyme
responsible for photosynthesis, while Junipers are C3 plants that rely on the
natural CO2 concentrations of the environment, although they are less
efficient at fixing CO2 in general. Damage done by J. virginiana includes
outcompeting forage species in pastureland. The low branches and wide
base occupy a significant portion of land area. The thick foliage blocks out
most light, so few plants can live under the canopy. The needles that fall raise
the pH of the soil, making it alkaline, which holds nutrients such as
phosphorus, making it harder for plants to absorb them. Juniperus virginiana has
been shown to remove nitrogen from the soil after invading prairies. It has
also been found to reduce carbon stores in the soil. This reduction in soil
nutrients also reduces the amount and diversity of microbial activity in the
soil. Cedar waxwings are fond of the "berries"
of these junipers. It takes about 12 minutes for their seeds to pass through
the birds' guts, and seeds that have been consumed by this bird have levels
of germination roughly three times higher than those of seeds the birds did
not eat. Many other birds and many mammals also consume them.
Uses The fine-grained, soft brittle pinkish-
to brownish-red heartwood is fragrant, very light and very durable, even in
contact with soil. Because of its rot resistance, the wood is used for fence
posts. The aromatic wood is avoided by moths, so it is in demand as lining for
clothes chests and closets, often referred to as cedar closets and cedar
chests. If correctly prepared, it makes excellent English longbows, flatbows,
and Native American sinew-backed bows. The wood is marketed as "eastern
redcedar" or "aromatic cedar". The best portions of the heartwood are one of the
few woods good for making pencils, but the supply had diminished sufficiently
by the 1940s that it was largely replaced by incense-cedar.
Juniper oil is distilled from the wood, twigs and leaves. The essential oil
contains cedrol which has toxic and possibly carcinogenic properties. The
cones are used to flavor gin. Native American tribes have historically
used juniper wood poles to mark out agreed tribal hunting territories.
French traders named Baton Rouge, Louisiana, from the reddish color of
these poles. It is still used in ceremony by some Nations.
During the Dust Bowl drought of the 1930s, the Prairie States Forest Project
encouraged farmers to plant shelterbelts made of eastern juniper throughout the
Great Plains. They grow well under adverse conditions. Both drought
tolerant and cold tolerant, they grow well in rocky, sandy, and clay
substrate. Competition between trees is minimal, so they can be planted in
tightly spaced rows, and the trees still grow to full height, creating a solid
windbreak in a short time. A number of cultivars have been selected
for garden planting, including 'Canaertii' 'Corcorcor', 'Goldspire',
and 'Kobold'. Some cultivars previously listed under this species, notably
'Skyrocket', are actually cultivars of J. scopulorum.
In the Missouri and Arkansas Ozarks, eastern juniper is commonly used as a
Christmas tree. Allergen
The pollen is a known allergen, although not as potent as that of the related
Juniperus ashei, which sheds pollen a month earlier. People allergic to one
are usually allergic to both. J. virginiana sheds pollen as early as late
winter and through early spring. Consequently, what begins as an allergy
to Ashe juniper in the winter may extend into spring, since the pollination of
the eastern juniper follows that of the Ashe juniper.
Contact with the leaves or wood can produce a mild skin rash in some
individuals. See also
Cedar wood References
External links PollenLibrary.com - Red Cedar
distribution map and allergen information
USDA Forest Service: Silvics of Trees of North America: Juniperus virginiana
Interactive Distribution Map of Juniperus virginiana