Interesting question, and probably one that is impossible to answer in a
meaningful way. I suspect we need to define what "discovered"
means. The question also potentially requires defining what is
an "Iris". There has been a lot of discussion as to the history of Iris as
related to humans, but most of it probably just scratches the surface, and it
usually only includes written history.
One answer would have to do with naming or recording Iris in some
way. As mentioned Linneaus named Iris (several of them), and his names are
the first ones we consider "official" or "legal" now. In this case the
"discoverer" might be Linnaeus or whoever collected his specimens. To me
this doesn't really work, because as already mentioned, Iris figured prominently
in history and culture in the Middle East, Asia, Europe, and northern Africa
(perhaps in America too?) thousands of years before Linnaeus was born.
Linnaeus is a late comer in this respect. All those earlier people surely
had names for their Iris, and they would consider the idea that Iris weren't
"discovered" until hundreds or thousands of years after they died rather
ridiculous (I suspect). To me, they wouldn't even be close to the first,
and the when would be much earlier.
In North America, I'd guess it was about 40,000 to 60,000 years ago, but
some people don't have people arriving on the continent until much later (hard
to believe, for me). The official answer as to the first namer of an
American Iris might again be Linnaeus, but I'm not sure about that, some
European soon after, if not him. But this is the wrong side of the world,
just a late foot note.
My prefered answer might also seem ridiculous at first glance, and it
borders on getting into the debate about evolution vs. creationism, and so
perhaps it isn't really much of an answer. Even so, I'd almost be willing
to say that the first person who was truly human (who, when and where was he,
and how do we define "truly human"?) probaby knew of, saw, and perhaps used some
sort of "Iris". So, by my reckonning, the first person to discover an Iris
might not even quite fit our modern definition of a person; it was probably
around a few hundred thousand years ago; and he (or she) was probably in Africa
Plants called "Iris" (or another synonymous vernacular
name), belonging to the Iris family, and with Iris type
flowers occur accross much of the world, including Africa and Eurasia, so
the earliest people in Africa were probably quite familiar with them. What
we consider to belong to the genus Iris now is a bit arbitrary, and gets changed
a bit now and then. In Africa our current definition of the genus leaves
out all but a few northern species, so if we limit the definition of an "Iris"
in this way, the answer likely becomes the first people who reached northern
Africa and/or Eurasia. Of course back when people were becoming people,
climates were likely somewhat different, and Iris of the genus Iris may have
actually occured further south into Africa (or less far?), so it still might be
people who were in the process of becoming people that were already familiar
That was sort of a hypothetical answer for what must be a hypothetical
question, but nonetheless I think it is a real answer.
We could get into religious histories, in which case the first person
allowed to exist in each religion (such as Adam), probably knew Iris. Not
sure when Adam would have lived - quite a long time ago.
It might be interesting to speculate on which was the first Iris to be
known, but this might be difficult too. Especially if my answer is used,
because at that time, some of the species may have not even been the same; they
could have changed some since then.
Hope y'all don't mind my having a little fun with the question.