BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Cornus florida | Flowering Dogwood 



GENERAL BOTANICAL CHARACTERISTICS : 
Flowering dogwood is a multibranched shrub or small tree that commonly
reaches 16 to 49 feet (5-15 m) in height [31,76].  In the South, plants
may grow 40 feet (12 m) tall with a d.b.h. of 18 inches (46 cm) [61],
but in the North, flowering dogwood more often grows as a multibranched
shrub, reaching heights of 10 to 13 feet (3-4 m) [86].  Flowering
dogwood is characterized by a broad, rounded crown [21,32].  Several
trunks may develop from a single root crown [76].  Rooting depths are
generally shallow and often less than 3 feet (1 m) [1].  The large,
simple, opposite leaves generally average 2 to 6 inches (5-15 cm) in
length [61].

Fruit is a glabrous, smooth, yellow to red, berrylike drupe [87] that
averages 0.6 inch (1.5 cm) in length and are borne in clusters of two to
six [32,79].  Flowering dogwood fruit tends to be heavier at higher
latitudes [99].  Each drupe contains one to two cream-colored, ellipsoid
seeds averaging 0.3 to 0.4 inch (7-9 mm) in length [33,87].

Important distinctions between commonly recognized varieties and forms
are summarized below [60,65,79]:

            var. urbiniana - bracts narrower, twigs grayer, with
                           larger drupes.
            var. pringlei - bracts fused.
            f. xanthocarpa -  drupes yellow.
            f. rubra - red involucral bracts.   


RAUNKIAER LIFE FORM : 
   Undisturbed State:  Phanerophyte (mesophanerophyte)
   Undisturbed State:  Phanerophyte (microphanerophyte)
   Burned or Clipped State:  Chamaephyte
   Burned or Clipped State:  Hemicryptophyte


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 [9,65,73].  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
[65].  Good seed crops are produced every 2 years, with crop failures
likely in 1 of 4 years [56].  Pack [71] 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 [14].  Flowers are pollinated by beetles, bees, butterflies,
and flies [24].  Seeds are dispersed by birds, mammals, and gravity
[65].

Germination:  Flowering dogwood is characterized by delayed germination
due to embryo dormancy [65].  Under natural conditions, seeds overwinter
before germination occurs [72], and some seeds do not germinate until
the second spring [9].  Warm, moist stratification for 60 days followed
by long periods (120 days) of cold temperatures increases germination
[5,9].  Chemical or mechanical scarification can also promote
germination.  Results of specific germination tests are as follows [9]:

      test conditions               germ. energy         germ. 
light       duration          amount      period         capacity             

8 hrs.      60 days           14-45%      15-20 days     35 %

Seedling establishment:  Adequate soil moisture is necessary for
successful establishment and growth of flowering dogwood seedlings [44].
Seedling survival is generally best on moist, rich, well-drained soils
[56] and at stand margins [65].

Vegetative regeneration:  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
[31,65] [see Management Considerations - mechanical treatment].  Greater
sprout height growth has been correlated with increasing stump diameter
[65].  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 [33].
Flowering dogwood also reproduces through layering [65].  Epicormic
branching has been reported [28].


SITE CHARACTERISTICS : 
Flowering dogwood grows in mesic deciduous woods, on floodplains,
slopes, bluffs, and in ravines [33,87,100].  It also occurs in gum
swamps, along fencerows, and in oldfield communities [15].  Growth is
often poor on dry, upland slopes and ridges [65].  Flowering dogwood
grows as an understory associate in many hardwood and conifer forests
throughout eastern North America [65].

Plant associates:  In addition to those identified in the Distribution
and Occurrence slot, common overstory associates include scarlet oak
(Quercus coccinea), southern red oak (Q. falcata), post oak (Q.
stellata), pitch pine (Pinus rigida), slash pine (P. elliottii),
Virginia pine (P.  virginiana), black gum (Nyssa sylvatica), sweetgum
(Liquidambar styraciflua), yellow poplar (Liriodendron tulipfera),
sassafras (Sassafras albidum), persimmon (Diospyros virginiana), red
maple (Acer rubrum) [37,65].  Understory associates are numerous and
often include serviceberry (Amelanchier spp.), blueberries (Vaccinium
spp.), and brambles (Rubus spp.) [8,46].

Soils:  Flowering dogwood occurs on soils that vary from moist, deep
soils to light-textured, well-drained upland soils [65] but most
commonly occurs on coarse to medium-textured acidic soils [2,86].
Abundance generally increases with better drainage and lighter soil
textures.  It is often virtually absent on heavy, poorly drained soils
[65].  Soil pH generally ranges from 6 to 7 [28].  Common parent
materials include gravel, sandstone, and limestone [87].

Elevation:  In the southern Appalachians, flowering dogwood grows from
sea level to 4,931 feet (0-1,500 m) [22] but does best on flats and
lower or middle slopes from 1,000 to 4,000 feet (304-1,219 m) in
elevation [28].  In the Great Smoky Mountains flowering dogwood grows
below 3,000 feet (<914 m) [96].


SUCCESSIONAL STATUS : 
Flowering dogwood is very tolerant of shade and is capable of persisting
beneath a forest canopy [65].  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 [93].
Flowering dogwood is physiologically plastic [93] and can also occupy
seral communities such as certain clearcuts and oldfield communities
[3,64].  It also grows in seral, fire-maintained sandhill communities
[67].  McDonnell [64] observed that flowering dogwood was absent until
the third year after fields were abandoned but continued to invade
through the twelfth year of the study.  Scattered patches of flowering
dogwood are common in young fields [64].  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
[26,67,75].  It is present in old-growth white oak forests of
southwestern Pennsylvania and in old-growth beech-oak stands of South
Carolina [47].  In parts of the South, flowering dogwood commonly grows
in pine stands which are seral to climax hardwood forests [28].
Billings [7] reported that it commonly appears when shortleaf pine
stands are 40 to 50 years old.  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 [41].



SEASONAL DEVELOPMENT : 
Vegetatative growth occurs throughout most of the summer but may cease
during periods of adverse weather conditions [56].  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
[65].  Growth was most rapid during the first week of August [65].
Laboratory tests indicate that short day lengths can force plants into
premature dormancy [28].  Rapid diameter growth typically lasts 80 to 90
days [28].  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 [36].  Flowers develop with
[86,87] or before the leaves [61].  In Ohio, Gorchov [103] reported a
mean average of 138 days between flowering and fruit ripening.
Flowering typically occurs in mid-March in the South and as late as May
in the North [65].  Flowering and fruiting dates by geographic location
are as follows:

Location          Flowering               Fruiting    Authority

FL Panhandle      April-June              ----        Clewell 1985
Great Plains      March-May               ----        Great Plains Flora 
                                                      Association 1986
NC, SC            March-April             Sept.-Oct.  Radford & others 1968
n-c Plains        April-May               late Sept.  Stephens 1973
New England       May 8-June 12           ----        Seymour 1985
ON                late May                Aug.-Sept.  Soper & Heimburger 1982
TX                late March-early May    Sept.       Simpson 1988, Lesser &  
                                                      Wistendahl 1974
WV                ----                    Sept.       Pack 1942

Seed dispersal occurs from mid-October to November or later [56].  In
West Virginia, latest fruit persistence was recorded on December 2; in
Texas, some seed persisted until January [56].  Leaves turn a deep red
in late September [87] and leaf fall occurs from early October to early
November [28].

Related categories for Species: Cornus florida | Flowering Dogwood