Stitch pattern used in Starflower Hat by Connie Chang Chinchio in Textured Stitches*, modified for use as an insertion. Also appears as pattern #187 in 1000 Knitting Patterns Book*. Could be worked flat or in the round. See also this blog post.
*Affiliate links. Buy a book and I get a couple pennies.
Shown with a cast-on count of 37 stitches.