I don't know about you,
but one of the things I appreciate most in a plant, that is, if I'm going
to be expending the effort to plant and cultivate it, is
enthusiasm.
That's why the Yellow Flag
Iris, iris pseudacorus is one of my all-time favorites. In
fact, this iris shows so much enthusiasm that it's considered an invasive
nuisance in some areas.
More on this later, first
a little background:
HISTORY
Yellow Flags are most probably the flower represented by
the fleur-de-lis a design that dates back to ancient Mesopotamia, over six
thousand years ago. I say "probably" because there exists a school
of thought that says the fleur-de-lis was, in fact, a lily. However,
even though the design we know today bears little resemblance to either
plant, one has to recall that photography was not highly advanced six
millenniums past. A pressed and dried iris pseudacorus, on the other
hand, looks quite a lot like a fleur-de-lis in its flattened state.
Further, the fleur-de-lis is most often found in heraldry on a blue
background, symbolizing water, where the plant thrives.
While some claim the French term fleur-de-lis came from
fleur-de-lys, or flower of the lily, I think its more likely to have
originated from the name of the French river Lis.

In the twelfth century, either King Louis VI or King Louis
VII (sources disagree) became the first French monarch to use the
fleur-de-lis on his shield. There are lots of pretty little stories
about how this came to be. The most credible, in my mind, is that
King Louis VI or King Louis VII found his army trapped and outnumbered,
where they had been driven to the shore of a large lake.

Seeing a continuous band of iris that stretched across the
lake at one point, Louis VI (or VII if you’re a stickler for detail)
realized that the band represented an area where the water wasn’t so deep
and his army made its escape by that route. Indeed, Yellow Flags do
not grow in water depths much greater than about 10 inches (25 cm.)
Needless to say, this bit of horticultural savvy earned Louis Six or
Seven an extremely high approval rating when he returned back home, and he
rewarded the flower by pasting fleurs-de-lis about willy-nilly.
If you don’t care to believe that story, there are others,
as I say, mostly involving God delivering a blue-backed fleur-de-lis flag
to Louis in person.