Pick enough violet flowers to fill a pint jar. Pour unseasoned white wine vinegar over the flowers. Put the lid on the jar and set aside on the counter for 4 days. Strain the liquid into another pint jar, put a lid on the jar and refrigerate.
For salad dressing:
1/2 cup mayonnaise
1 teaspoon sugar
1 tablespoon plus 1 teaspoon violet vinegar
Mix well and serve over salad greens.