Someone should have an answer for you since most Japanese iris are 3 feet+

Ensata Gardens has a telephone number on their home page. They would know.

Here is a link that might be useful: http://www.ensata.com/

Might it have been I. tectorum?

{{gwi:1037936}}

It is a crested iris that has the same flat form and stays small. I've heard it referred to as the Japanese Root (or Roof) Iris in the past.

I don't know of any dwarf JIs (off the top of my head), but I do know that Bob Hollingworth is working on a line of dwarf SIBs. As I understand it, these aren't on the market yet, but they do exist.

Currier McEwan worked with dwarf sib. I bought a few of them years ago. They are surprisingly nice plants since they don't do the leaf elongation/flopping of normal siberians.

JIs are fairly picky about soil. Like anything else that wants acidic soil, they *do not* like me.