Smilax rotundifolia L.
Smilax rotundifolia L. var. crenulata Small & A. Heller
Smilax rotundifolia L. var. quadrangularis (Muhl. ex Willd.) Alph. Wood
Common greenbrier is a widespread North American native plant. (A brier is a thicket of thorny plants.)
Identification: This woody, thorned vine reaches 10-20' (3-6.1 m) in length, clambering over other plants, attaching itself with tendrils as it goes. It is deciduous, but may retain its leaves until late in the winter in the south. Stems are somewhat diamond-shaped in cross-section, with sharp thorns up to ¼" (8 mm) long. Leaves are glossy and leathery, with several fairly prominent veins running from the base to the tip of the leaf, round or oval in shape. Flowers are yellowish-green, about ¼" (6.3 mm) around. Fruits are clusters of blue berries with whitish coatings, about ¼" (6.3 mm) in diameter. The berries can persist through much of the winter.
Smilax rotundifolia on Southeastern Flora, the Southeastern U.S. Plant Identification Resource
Smilax rotundifolia on the USDA Forest Service's Fire Effects Information Database
Smilax rotundifolia on www.carolinanature.com
Smilax rotundifolia on islandcreekes.fcps.edu
Smilax rotundifolia at the Virginia Tech Department of Forest Resources and Environmental Conservation
Smilax rotundifolia on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Smilax rotundifolia on eFloras
Smilax rotundifolia description by Thomas H. Kent, last updated 25 May 2020.