Base rnd, each side: Multiple of 8 + 7 + corner sts.
Begin 4 sts to left of corner st.
Rnd 1: Ch 6 (counts as dc and ch-3), skip 2 sts, *[sc in next 3 sts, ch 3, skip 2 sts, dc in next st, ch 3, skip 2 sts] to 1 st before corner st, sc in next st, (sc, ch 3, dc, ch 3, sc) in corner st, sc in next st, ch 3, skip 2 sts**, dc in next st, ch 3, skip 2 sts; rep from * around, ending last rep at **, join with slip st to 3rd ch of ch-6.
Rnd 2: Ch 1, sc in same st, ch 7, *sc in next dc, ch 7; rep from * around, join with slip st to first sc.
Rnd 3: Ch 5 (counts as dc and ch-2), 3 sc in next ch-space, ch 2, *[dc in next sc, ch 2, 3 sc in next ch-space, ch 2] to corner st, (dc, ch 3, dc) in corner st, ch 2, 3 sc in next ch-space, ch 2; rep from * around, join with slip st to 3rd ch of ch-5.
Rnd 4: Ch 1, sc in same st, Picot-3, *[2 sc in next ch-space, sc in next 2 sc, Picot-3, sc in next sc, 2 sc in next ch-space**, sc in next dc, Picot-3] to corner space, 5 sc in corner space, sc in next dc, Picot-3; rep from * around, ending last rep at **, join with slip st to first sc. Fasten off.