Smilax rotundifolia L.

A vigorous, deciduous or partially evergreen climber, with slender, round or more or less angled stems, armed with one or two short spines between each leaf (not at the nodes); the stems are sometimes 6 or 8 yards long; branches four-angled. Leaves ovate to broadly heart-shaped; 2 to 6 in. long, often broader than long, with a short abrupt point, prominently five-nerved, glabrous and glossy green on both sides; stalk 1⁄4 to 1⁄2 in. long. Flowers greenish yellow, about 1⁄5 in. across, borne in umbels; main flower-stalk 1⁄4 to 1⁄2 in. long, flattened. Berries roundish, black, 1⁄4 in. in diameter, covered with glaucous bloom, usually three to six of them in one cluster.

Native of eastern N. America; introduced in 1760. This is the commonest, most vigorous and hardy of all the smilaxes in cultivation, making a dense thicket of stems. It is the common horse brier or green brier of the United States, where its stems are sometimes 30 to 40 ft long, stretching from tree to tree. In gardens it may be trained up stout oak posts on which the stumps of the side branches have been left 2 or 3 ft long. Grown in this way it is very elegant.