Macrophotograph of the growing, apical stem of the bindweed, Convolvulus sp. , showing the spiral formation of immature leaves. Bindweed is a climber, a plant which grows from ground level to a height that is attained exclusively through the support of other plants or inanimate objects such as walls or wires. The twining action of bindweed results from the exaggerated, curved growth of the stem, rather than from some special sensitivity in the stem tip. This occurs in white bryony, Bryonia dioica, where the spiral binding results from a sensitive response of one side of the apical stem towards roughened, solid objects.