This canvaswork stitch is made up of asymmetrical crossing stitches where the second crossing stitch is half the width of the first, and each stich overlaps the preceding one.  Collectively they form what looks like a row of plaited braid.

Plait stitch was certainly in use in late medieval Europe: there is a whitework altar cloth from 14th century Germany (held by the Metropolitan Museum in New York) which features the stitch and the Victoria and Albert Museum in London holds a stole from a similar era.

Historical references to plait stitch can be hard to interpret as they may refer to long-armed cross stitch or plaited Gobelin stitch (or even heavy chain, or any other stitch which provides a braided line), rather than what we now call plait stitch.  The 17th century inventories of English needlework from Hardwick Hall contain such references.

More recently, plait stitch has featured in three Moroccan embroidery traditions: Chefchaouen embroidery, 19th century Salé embroidery where it was used extensively to render geometric designs and Azemmour embroidery which uses it in negative design counted thread work.