1. (noun) convolvulus, bindweed, New Zealand bindweed, Calystegia sepium - a herbaceous perennial that twines around other plants to a height of up to 2-4 m. Leaves are arranged spirally, simple, pointed at the tip and arrowhead shaped, 5-10 cm long and 3-7 cm broad. Flowers are produced from late spring to the end of summer. The open flowers are trumpet-shaped, 3-7 cm diameter, white, or pale pink with white stripes. A name given to several climbing plants.