Though reminiscent of the Tufted vetch this is distinguished by its hairless leaves and shorter flowering raceme. It is widespread in rough grassland, hedges and thickets throughout virtually the whole of Scotland.
The leaves have between 5 and 9 pairs of leaflets narrowly egg-shaped, ending in a tendril. The stems are erect and can hold themselves up if they have to, but they use the tendrils to cling to other plants to gain height.
The flowers are standard pea flower shapes, with 5 petals, forming one at the top, two at the sides and two fused together at the base forming the ‘tongue’ of the flower. Colour is purple and length is about 1.5 cm. Hidden inside the calyx are 10 stamens.
The fruit ripens into a black or dark brown legume, or pod, smooth and fat, and about 3 cm long. It contains 4-8 tiny peas.
Bush vetch is a favourite of both bumblebees and honeybees. It also attracts ants by means of nectaries located at the stipules of leaves. All this potential insect pollinating activity is superfluous as it spreads by means of underground runners.