Tied Herringbone Stitch
Several variations: 1. Tacked down with small Straight Stitches, 2. Tacked down with Detached Chain Stitches, 3. Zigzag Coral Stitch worked over the Herringbone Stitch. The same methods of tying down can be used as well with Closed Herringbone.
Mary Thomas's Dictionary of Embroidery Stitches, p 121 The Stitches of Creative Embroidery, p 80