This pattern is very simple, but very delicate and effective.
It’s a variation of Diagonal Fern Lace, page 211, Treasury of Pattern by Barbara Walker.
I omitted the P2 between each repeat, In so doing, the wavy lines are more pronounced.

errata: Thanks to my good angel with sharp eye Guarionex
it should be:

Row 2: * K9, Yo, K1, Yo, K3, Sl1, K2tog, psso; rep from*
Row 4: * K10, Yo, K1, Yo, K2, Sl1, K2tog, psso; rep from*