Another of the common flowers seen on the banks of the Oxford Canal is the scrambling vicia cracca, the tufted or cow vetch.
Cow Vetch is a fast-growing perennial and flowers prolifically from late Spring to late Summer, sending out cascades of pea-flower shaped purple to violet flowers from the leaf axil.
It has limited capacity for vegetative spread and is mainly reliant upon it large seed for regeneration, this coupled with its need for surrounding vegetation to act as it’s support means it is rarely found in pasture or mown grassland.
It can, however, become established in meadowland, particularly those meadows cut later in the season, and thrives in hedgerows, woodland edges, rough grassland and on river/canal banks. It has a preference for reasonably fertile, damp soils but is intolerant of permanently damp sites.
Cow Vetch is similar to a pea in growth habit. It climbs by means of branched tendrils found on the ends of its ladder like leaves which are divided into 8-12 pairs of leaflets. When the tendrils come into contact with another plant it has the ability to lash it’s tendrils to them. This can cause the strangling of smaller plants.
An individual plant may reach a length (or height) of 2 m and its tap root may extend up to 1 m. The leaves are 3-8 cm long, and each leaflet 5-10 mm long.
When the flowers drop off a tiny bright green seed pod starts to form. The seed pods are approx. 2 cm long, and like the flowers, resemble those of a small pea. Un-ripened seeds are swollen and have a green tint to them, but they un-swell as they become ripe. The seed pods may vary in colour from light brown to dark brown with black spots.
Cow vetch is pollinated by bumble bees and other large bees.
In the US, it is widely used as a forage crop for cattle, and is beneficial to other plants because, like other leguminous plants, it enriches the soil in which it grows by its nitrogen-fixing properties. Cow Vetch is also much appreciated by butterflies as a source of nectar.
Owners of pet birds such as budgerigars often use Cow Vetch as a nutritious food; the birds are especially fond of the seeds but may also eat the foliage, in America this earned it the nickname Bird Vetch.
Other posts in this series can be found HERE.