Thalictrum 39black stockings39 is a tall willowy perennial that produces an abundance of fluffy mauve flowers on glistening black stems during the height of summer meadow rue is perfect for filling gaps in woodland gardens and shaded borders particularly as the elegant foliage provides an ideal backdrop for smaller perennials thalictrum plants can be incorporated into your shady border with almost any other plant companions could include hostas ferns or even larger45leaved plants