Nodo Erculeo is usually translated as Herakles Knot in English, as
it is far more common in Greek than in Roman decoration. It is also a
square knot to Boy Scouts and a reef knot to sailors.
The Greeks called it a Herakles Knot because it was considered such
a strong knot. Of course, as sailors know, it is not an especially
strong knot and can easily be collapsed into a lark's head on a line.
The motif goes back well into antiquity. I suspect the reference to
4th cent. Taranto is actually to 4th cent. BC Taranto. Taranto was
founded by Spartan emigrants in 706 BC and called Taras. It was one
of the leading cities of Magna Graecia. One legend has it that the
city was founded by Herakles. Equally likely, to my mind, is that the
ornament first became prominent in the nearby city of Herakleia, just
across the Gulf of Taranto, founded in the 5th cent. BC.
Wherever the Herakles Knot was first used as an ornamental motif it
is often found as a feature on Classical and Helenistic jewelry. Here
is a gold armband in the Metropolitan Museum with the knot inlaid
with garnet. Note the florettes and palm frond similar in style and
placement to that in the Tidbits knot.
I think the humor alluded to in your Italian article may be in the
juxtaposition, one might even say incongruity, of delicate
scrollwork and floral motifs on a knot symbolic of the power of