Base rnd, each side: Multiple of 8 + 3 + corner sts.
Begin 4 sts to left of corner st.
Rnd 1: Ch 1, sc in same st, ch 5, skip 3 sts, *[sc in next st, ch 5, skip 3 sts] to corner st, (sc, ch 3, sc) in corner st, ch 5, skip 3 sts; rep from * around, join with slip st to first sc.
Rnd 2: Ch 1, sc in same st, ch 5, *sc in next sc, ch 5; rep from * around, join with slip st to first sc, slip st in next ch-space.
Rnd 3: Ch 3 (counts as dc), (3 dc, Picot-3, Picot-5, Picot-3, 4 dc) in same space, *(2 sc, ch 3, 2 sc) in next ch-space**, (4 dc, Picot-3, Picot-5, Picot-3, 4 dc) in next ch-space; rep from * around, ending last rep at **, join with slip st to top of ch-3. Fasten off.