Cow vetch

Cow vetch is similar to a pea in growth habit, sending out noose-like branched tendrils from the tips of its leaves when it contacts another plant and securely fastens itself. This can cause strangling of smaller plants. An individual plant may reach a length of 2 m and its taproot may extend up to 1 m. The leaves are 3–8 cm long, pinnate, with 8–12 pairs of leaflets, each leaflet 5–10 mm long. The plant is fast-growing and flowers prolifically, sending out 10 to 40 flowered one-sided racemes cascading pea-flower shaped purple to violet flowers from the leaf axil during its late spring to late summer flowering period. The flowers drop off and tiny bright green seed pods 10 - 20 mm long,start to form. The seed pods are 2 cm long and contain 6 to 8 seeds. They resemble those of a very small pea. The tiny seeds within are ripe when the pods have turned black. Unripened seeds are swollen and have a green tint to them, but they unswell when they become ripe. The seed pods vary from light brown to dark brown with black spots.