I just read the advice about info that helps ID iris. I will go get more data.

I'm a newbie as far as Iris are concerned, and am not sure how to answer irisgal's questions. I hope these photos will help.

Your bitone purple has an interesting beard. It looks very soft going from dull mustard out to pale lavender. That is always an area to pay attention to, along with the veining around it. I don't see purple base foliage at ground level. In the next to last picture the stalk looks to have 3 branches with double sockets on the terminal (top) flower and on the lowest branch. Maybe more ? Can't tell. Fall color has red pigment and the color lightens towards the edges. Height looks more than 27 inches and if so it is a tall bearded, not an intermediate. Oh, and the standard petals look relaxed, almost resting on one another. This may change with weather, age of bloom, or be a trait.

I checked pre 1959 pictures.
Indian Hills - fairly good match but no stalk pictures and not sure if veined area shape matches. Falls seem a little droopier.
Concord Velvet - only saw one pic so inconclusive.
Master Charles - looks to have more red pigment than yours.
Sable - didn't see enuf red pigment, matches in some areas.
The Black Douglas - possibility.

Here are places to research. Good luck.

http://www.historiciris.org/

http://wiki.irises.org/bin/view/Main/TallBearded

Irisgal, thank you very much! I knew that I don't know anything about Irises, but you make it clear that they are a complicated business! I'll check out your links. Thanks again.

You are welcome!