supplejack, any of various woody climbing plants with pliant, tough stems, particularly Berchemia scandens, of the buckthorn family (Rhamnaceae), also known as rattan vine. B. scandens occurs in the central and southern United States. It climbs to the tops of trees and has alternate, elliptical (oblong oval) leaves 3–7.5 cm (1.25–3 inches) long. The small, greenish white flowers are borne in a terminal cluster; the bluish black fruit is about 1 cm in diameter.