- Name also: Climbing Buckwheat, Wild Buckwheat, Bearbind, Cornbind, Black-bindweed
- Family: Dock Family – Polygonaceae
- Growing form: Annual herb
- Height: Twining stems usu. less than 1 m (3.3 ft.) long.
- Flower: Regular, 2–3 mm (ca. 0.1 in.) wide. Perianth consists of usu. 5 greenish segments arranged in two whorls. The three segments of the outer whorl are papillose and rough, have pink or white margins, and lack a dorsal wing. Flower-stalk and perianth grow after flowering. Carpels 2 or 3, completely fused. Stamens 8. Flowers in whorled group-like cymes.
- Leaves: Alternate. Stalked, both sides rough but hairless. Blade triangular, arrow-shaped, 2–8 cm (0.8–3 in.) long, pointed, and the basal lobes usu. acute. Stipules fused into a membranous stem-enclosing sheath (an ochrea) that is situated above the point where the leaf-stalk is attached.
- Fruit: Three-angled, black, granular, winged achene, remains enclosed by the perianth. Node near the end of the fruit-stalk.
- Habitat: Fields, gardens, roadsides, disturbed ground, rubbish tips, and rock outcrops.
- Flowering time: July-September.
Black bindweed is an annual, and often a troublesome weed. It prefers dry mineral soil. When the plant finds a stout support it starts to twine, first anticlockwise, later clockwise. The seeds of this species were formerly used as food. Humans are their most efficient dispersers.
Black bindweed’s southern look-alike, copse-bindweed can be distinguished by that its outer perianth segments have a dorsal wing and they are smooth, the leaves are more triangular, and the stem usually smooth.