common greenbriar (Smilax rotundifolia)
Smilax rotundifolia L. var. crenulata Small & A. Heller
Smilax rotundifolia L. var. quadrangularis (Muhl. ex Willd.) Alph. Wood
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name for common green-
brier is Smilax rotundifolia L. Some authors recognize a variant: Smilax
rotundifolia var. quadrangularis (Muhl.) Wood.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: Common greenbrier
is a native, woody vine which uses tendrils to climb 10 to 20 feet (3-6 m).
The leathery leaves are deciduous, although sometimes tardily so in the
southeastern states. The stems are usually quadrangular and diffusely
branched with flattened prickles up to 0.3 inches (0.8 cm) long. The fruit
is a berry. Common greenbrier has long, slender, nontuberous rhizomes
near the soil surface. Common greenbrier canes live 2 to 4 years.
REGENERATION PROCESS: Common greenbrier regenerates by
rhizomes and seed. Rhizomes persist for years after the plant has been
top-killed by fire or other disturbance. Common greenbrier produces
some fruit every year. Seeds are dispersed by animals and water. Seeds
often germinate when disturbance increases the amount of light on the
soil and brings buried seeds to the surface.
SITE CHARACTERISTICS: Common greenbrier is generally a sub-
mesic species, but extends onto subxeric and xeric sites. It occurs on a
wide variety of sites; these include south slopes and ridgetops in the
southern Appalachian Mountains, low damp flatwoods on the lower
Atlantic Coastal Plain, the inland coastal plain of Nova Scotia, and banks
of freshwater swamps in Massachusetts. Optimum soil pH is 5.0 to 6.0.
SUCCESSIONAL STATUS: Common greenbrier is a pioneering species
as well as a component of forest understories. Although it grows in low light
conditions, common greenbrier is also capable of relatively high photosyn-
thetic rates in full sunlight. Shading of 10 to 20 percent of full sunlight may
be optimal, but good fruit production occurred in 70 to 80 percent shade in
Common greenbrier is often found on recently logged sites, roadsides, and
old fields. Once vines such as common greenbrier become established on
disturbed sites, they may dominate the early successional stages.
SEASONAL DEVELOPMENT: Common greenbrier flowers from April
to May in the southeastern states, from May to June in the northeastern
states, and in June in southern Canada. Fruits ripen in the fall. All annual
growth is completed in a short time in the spring.
GENERAL DISTRIBUTION: Common greenbrier occurs throughout
the eastern United States. Its range extends as far north as southern Nova
Scotia and southern Ontario and continues west to southern Michigan,
Indiana, and southern Illinois; south through southeastern Missouri to
eastern Texas; and east to northern Florida.
SKY MEADOWS DISTRIBUTION:
Vine 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: Common green-
brier occurs in a wide variety of plant communities. Understory associates
of common greenbrier in moist woods include mapleleaf viburnum (Vibur-
num acerifolium), grape (Vitis spp.), flowering dogwood (Cornus florida),
New York fern (Thelypteris noveboracensis), cat greenbrier (Smilax
glauca), cane (Arundinaria gigantea), eastern poison-ivy (Toxicodendron
radicans), and Virginia creeper (Parthenocissus quinquefolia).
In Atlantic white-cedar (Chamaecyparis thyoides) communities in North
Carolina, common greenbrier occurs with sweetbay (Magnolia virginiana),
redbay (Persea borbonia), large gallberry (Ilex coriacea), hurrahbush
(Lyonia lucida), blueberry (Vaccinium spp.), and cinnamon fern (Osmunda
In drier woods, heath balds, heath-shrub communities, and rhododendron (Rhododendron spp.) thickets, common greenbrier occurs with black
huckleberry (Gaylussacia baccata), hillside blueberry (Vaccinium
pallidum), and low sweet blueberry (Vaccinium angustifolia). Other
associates of dry sites include mountain-laurel (Kalmia latifolia), swamp
dog-laurel (Leucothoe axillaris), Carolina holly (Ilex ambigua), and
mountain white-alder (Clethra acuminata).
Common greenbrier occurs in old fields with black locust (Robinia
pseudoacacia), sassafras (Sassafras albidum), blackberry (Rubus spp.),
blueberry, and bracken fern (Pteridium aquilinum).
IMPORTANCE AND USES: Numerous birds and animals eat common
greenbrier fruits. The persistent fruits are an important late winter and
early spring food for wintering birds including northern cardinals and
white-throated sparrows. White-tailed deer and lagomorphs browse the
green canes, tender shoots, and leaves.
Common greenbrier forms impenetrable thickets of prickly branches which
probably create good cover for small mammals and birds.
Researchers recommend common greenbrier and other clonal shrubs for
right-of-way clearings where trees interfere with powerlines. Dense
common greenbrier, hillside blueberry, and black huckleberry thickets
resisted invasion of trees for at least 15 years in a right-of-way from which
trees were originally removed by herbicide application.
Crooked Run Valley