This is ruching--you sew stitches at 90 degree angles and pull it up to gather and make the ric-rac design. See the link below--it shows how to do it and you can down load a pdf. http://www.roserushbrooke.com/how-to-ruche.html
This one shows how to make a gathered leaf and ruched flower. Also a pdf. http://butasaumur.is/wp-content/uplo...-bl%C3%B3m.pdf
Hope this helps!