Crooked Run Valley
flowering dogwood (Cornus florida)
SCIENTIFIC SYNONYMS: There are no scientific synonyms for
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name is Cornus florida
L. Earlier taxonomists recognized several subspecies or varieties,
but most are no longer accepted. The following varieties are currently
recognized by many authorities: 1) Cornus florida var. urbiniana Wang.,
2) Cornus florida var. florida, and 3) Cornus florida var. pringlei. These
varieties are distinguished primarily on the basis of differences in floral
and vegetative morphology. Several forms, including those with pink or
yellow flowers and red or yellow fruit, have been identified. Commonly
recognized forms are as follows: 1) Cornus florida f. rubra (Weston) Palmer
& Steyeim., 2) Cornus florida f. xanthocarpa Rehder, 3) Cornus florida f.
pendula (Dipp.) Schelle, and 4) Cornus florida f. pluribracteata Rehder.
Flowering dogwood is not known to hybridize with any other species.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: Flowering dogwood
is a multibranched shrub or small tree that commonly reaches 16 to 49 feet
(5-15 m) in height. In the South, plants may grow 40 feet (12 m) tall with a
d.b.h. of 18 inches (46 cm), but in the North, flowering dogwood more often
grows as a multibranched shrub, reaching heights of 10 to 13 feet (3-4 m).
Flowering dogwood is characterized by a broad, rounded crown. Several
trunks may develop from a single root crown. Rooting depths are generally
shallow and often less than 3 feet (1 m). The large, simple, opposite leaves
generally average 2 to 6 inches (5-15 cm) in length. Fruit is a glabrous,
smooth, yellow to red, berrylike drupe that averages 0.6 inch (1.5 cm) in
length and are borne in clusters of two to six. Flowering dogwood fruit tends
to be heavier at higher latitudes. Each drupe contains one to two cream-
colored, ellipsoid seeds averaging 0.3 to 0.4 inch (7-9 mm) in length.
In the mountainous regions of Virginia, flowering dogwood will often develop
rusty-red splotches on flower blossoms in late April. This indicates the tree
has been infected with the exotic invasive fungus Discula destructiva,
commonly called dogwood anthracnose. Since its introduction in New York
in the late 1970s, dogwood anthracnose may have already destroyed more
than half of the native dogwoods in the Appalachian Mountains. Central
maryland has lost almost 75% of its dogwoods while 80% of Northern
Virginia mountain dogwoods are gone. In some areas the tree has vanished.
REGENERATION PROCESSES: Flowering dogwood reproduces
through seed as well as by vegetative means. Seed: Plants grown from
seed often produce seed as early as 6 years of age. Six-year old sprouts
with a diameter of 0.75 inch (19 mm) and height of 4 feet (1.2 m) have
also reportedly produced seed. Good seed crops are produced every 2
years, with crop failures likely in 1 of 4 years. Pack reported that 71
percent of all plants bore fruit during a single year, with average yields
of 0.50 quart (0.4 l). An annual average of 1,417 fruits per acre (3,500/ha)
was reported in oak- hickory stands and up to 27,530 per acre (68,000/ha)
in openings. Flowers are pollinated by beetles, bees, butterflies, and flies.
Seeds are dispersed by birds, mammals, and gravity.
Flowering dogwood is characterized by delayed germination due to embryo
dormancy. Under natural conditions, seeds overwinter before germination
occurs , and some seeds do not germinate until the second spring. Warm,
moist stratification for 60 days followed by long periods (120 days) of cold
temperatures increases germination. Chemical or mechanical scarification
can also promote germination.
Seedling establishment: Adequate soil moisture is necessary for successful
establishment and growth of flowering dogwood seedlings. Seedling survival
is generally best on moist, rich, well-drained soils and at stand margins.
Flowering dogwood often sprouts vigorously after plants are cut or
burned. Plants sprout best after winter fellings; those cut in midsummer
produce the fewest stump sprouts. Greater sprout height growth has
been correlated with increasing stump diameter. An increase of 0.3 feet
(9 cm) has been reported for every 1 inch (2.5 cm) increase in stump
diameter. Sprouting from the root crown has been reported after fire.
Multiple stems commonly develop from a single surviving root crown.
Flowering dogwood also reproduces through layering.
SITE CHARACTERISTICS: Flowering dogwood grows in mesic
deciduous woods, on floodplains, slopes, bluffs, and in ravines. It also
occurs in gum swamps, along fencerows, and in oldfield communities.
Growth is often poor on dry, upland slopes and ridges. Flowering dogwood
grows as an understory associate in many hardwood and conifer forests
throughout eastern North America.
Common overstory associates include scarlet oak (Quercus coccinea),
southern red oak (Quercus falcata), post oak (Quercus stellata), pitch pine
(Pinus rigida), slash pine (Pinus elliottii), Virginia pine (Pinus virginiana),
black gum (Nyssa sylvatica), sweetgum (Liquidambar styraciflua), yellow
poplar (Liriodendron tulipifera), sassafras (Sassafras albidum), persimmon
(Diospyros virginiana), red maple (Acer rubrum). Understory associates
are numerous and often include serviceberry (Amelanchier spp.), blue-
berries (Vaccinium spp.), and brambles (Rubus spp.).
Flowering dogwood occurs on soils that vary from moist, deep soils to light-
textured, well-drained upland soils but most commonly occurs on coarse to
medium-textured acidic soils. Abundance generally increases with better
drainage and lighter soil textures. It is often virtually absent on heavy,
poorly drained soils. Soil pH generally ranges from 6 to 7. Common parent
materials include gravel, sandstone, and limestone.
In the southern Appalachians, flowering dogwood grows from sea level to
4,931 feet (0-1,500 m) but does best on flats and lower or middle slopes
from 1,000 to 4,000 feet (304-1,219 m) in elevation. In the Great Smoky
Mountains flowering dogwood grows below 3,000 feet (<914 m).
SUCCESSIONAL STATUS: Flowering dogwood is very tolerant of shade
and is capable of persisting beneath a forest canopy. Although it commonly
grows as a suppressed understory tree, it is also important in gap closure
and grows in several strata in stands with a multicanopied structure.
Flowering dogwood is physiologically "plastic" and can occupy communities
such as certain clearcuts and oldfield communities. Scattered patches of
flowering dogwood are common in young fields. Because seed is primarily
bird-dispersed, seedling concentrations often occur beneath powerlines
and poles. Flowering dogwood occurs in climax magnolia-beech, magnolia-
holly hammock communities, and southern mixed hardwood stands in the
South. It is present in old-growth white oak forests of southwestern
Pennsylvania and in old-growth beech-oak stands of South Carolina.
In parts of the South, flowering dogwood commonly grows in pine stands
which are seral to climax hardwood forests. Flowering dogwood is typically
an important transitional species as pine is replaced by hardwoods in
southern mixed hardwood forests, but has been slow to reinvade these
types of stands in central Florida.
SEASONAL DEVELOPMENT: Vegetatative growth occurs throughout
most of the summer but may cease during periods of adverse weather
conditions. In a Massachusetts study, seedlings grew from April 24
through September 4, although 90 percent of the total growth took place
from May 15 through August 18. Growth was most rapid during the first
week of August. Rapid diameter growth typically lasts 80 to 90 days. New
floral and vegetative buds become evident in August, develop somewhat
during the summer months, remain dormant through the winter, and
expand the following spring. Flowers develop with or before the leaves.
Flowering typically occurs in mid-March in the South and as late as May
in the North. Seed dispersal occurs from mid-October to November or
later. In West Virginia, latest fruit persistence was recorded on December
2; in Texas, some seed persisted until January. Leaves turn a deep red in
late September and leaf fall occurs from early October to early November.
GENERAL DISTRIBUTION: Flowering dogwood grows from central
Florida northward to southwestern Maine and extends westward through
southern Ontario to central Michigan, central Illinois, Missouri, south-
eastern Kansas, eastern Oklahoma, and eastern Texas. The variety urbiniana
(or subspecies) is found in the mountains of Nuevo Leon and Veracruz in
eastern Mexico. The form xanthocarpa occurs in parts of New York.
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
HABITAT TYPES AND PLANT COMMUNITIES: Flowering
dogwood commonly grows as a scattered understory species in many
eastern deciduous or coniferous forests. It has been identified as and
important understory dominant or codominant in several eastern
hemlock (Tsuga canadensis) and white oak (Quercus alba) communities.
Spotted wintergreen (Chimaphila maculata) has been listed as a
IMPORTANCE AND USES: Flowering dogwood is a valuable species
for wildlife. Its fruit is readily eaten by many songbirds including the
hermit, olive-back, and gray-cheeked thrushes, veery, northern cardinal,
white-throated sparrow, tufted titmouse, towhees, grosbeaks, thrashers,
bluebirds, and juncos. The fruit is particularly important to the American
robin. Flocks often move from the forest edge to the interior as berries are
depleted. The pileated woodpecker, red-headed woodpecker, red-bellied
woodpecker, common crow, common grackle, and starling also seek out
flowering dogwood fruit. Value of fruit to upland game birds is rated as
good. In the Missouri Ozarks, flowering dogwood fruit is particularly
important to the wild turkey from September to February. Berries are
readily eaten by the eastern chipmunk, white-footed mouse, gray fox,
gray squirrel, black bear, beaver, white-tailed deer, skunks, and other
Beaver occasionally feed on flowering dogwood browse and sprouts are
often heavily browsed by rabbits. In southwestern Michigan, browse is
preferred by cottontail rabbits during the winter and in parts of Penn-
sylvania, flowering dogwood is considered an important deer browse.
Flowering dogwood provides good cover for many wildlife species.
Flowering has been planted on strip-mined lands in Indiana and grows
as volunteers on surface-mined lands in Missouri, Kansas, and Oklahoma.
The brownish wood of flowering dogwood is hard, strong, heavy, fine
grained, and shock resistant. It was formerly used for shuttles in the
textile industry, and has also been used for tool handles, charcoal, wheel
cogs, mauls, hay forks, and pulleys. The wood is occasionally used to
make specialty items such as golf club heads, turnery, roller-skate wheels,
jeweler's blocks, knitting needles, and woodcut blocks.
Flowering dogwood is highly valued as an ornamental and was first
cultivated in 1731. Showy blossoms and attractive fall foliage contribute
to its year-round beauty. It is widely used in landscaping and street
plantings. At least 20 cultivars are now available. Popular cultivars
include 'Sweetwater Red,' 'Silveredge,' 'White Cloud,' 'Spring Song,'
'Gigantea', and 'Welchii' which is characterized by unique yellow and
red variegated leaves.
Some Native American peoples made a scarlet dye from the roots of
flowering dogwood. Teas and quinine substitutes were made from the
bark. Plants contain cornine which is used medicinally in parts of Mexico.
The bright red fruits are poisonous to humans.
As noted above, flowering dogwood trees have been seriously depleted
throughout Northern Virginia due to the fugus Discula destructiva. This
reduction in the number of dogwood trees may significantly alter general
forest health. The flowering dogwood obtains calcium from the soil,
concentrating it in its leaves. When leaves drop and decay, the mineral
becomes available to other organism; in addition, it prevents acidification