Vicia cracca (tufted vetch, cow vetch, bird vetch, blue vetch, boreal vetch), is a species of vetch native to Europe and Asia. It occurs on other continents as an introduced species, including North America, where it is a common weed. It often occurs in disturbed habitats, including old-fields and roadside ditches.
Pea-like tendrils, climbing habit. 10-50 bright violet flowers on one side of stalk. Compound leaves.
Native lookalike: American vetch (https://inaturalist.ca/taxa/53320-Vicia-americana) has less flowers on both sides of stalk, smaller habit and toothed stipules.
2020-21: https://inaturalist.ca/observations?project_id=69401&taxon_id=52471&place_id=any&verifiable=any
2019-20: https://inaturalist.ca/observations?project_id=38602&taxon_id=52471&place_id=any&verifiable=any