Knotted buttonhole stitch
This stitch is a variation of buttonhole stitch: it is wider-spaced than a typical buttonhole stitch and has a knot at the end of each of the buttonhole’s ‘leg’.
It is often confused with knotted blanket stitch - an edging stitch with an additional knot in each buttonhole loop.
Leaving the needle in the fabric, bring the point up again on the base line, ensuring the needle goes over the base of the surface thread to anchor it (as you would for a normal buttonhole stitch).
Structure of stitch
A border stitch sometimes used to simulate fringing. It can also be used an edging stitch.
Mrs Archibald Christie, Samplers and Stitches (1921) , p.26
Mary Thomas’s Dictionary of Embroidery Stitches (1934) , p.24–5