Buttonhole stitch

Embroidery with stems in buttonhole and leaves in detached buttonhole stitch, worked in natural perle cotton on cotton-linen fabric, United States, 1990s.
Buttonhole stitch in embroidery
Raised buttonhole scallops, from Isabella Beeton's Beeton's Book of Needlework

Buttonhole stitch and the related blanket stitch are hand-sewing stitches used in tailoring, embroidery, and needle lace-making.