Syncopated Brioche Stitch
From the Stitch Description: “The fascinating Syncopated Brioche is a fluffy lace pattern when worked in a fine yarn on large needles, and a soft texture pattern when worked in medium-weight yarn…”
Location of Stitch: Chapter Eight: Patterns Made with Yarn-Over Stitches, page 158 from A Treasury of Knitting Patterns.
Also pointed out by Esther Bozak (and later illustrated by Fuzzy Galore) in her collection of reversible stitches for scarves.
You can see a photo of this stitch at The Walker Treasury Project.