I just posted a couple of pictures of iris on the Ask a question forum (though perhaps I should have posted on plant ID.... oops)
I souldn't mind repeated the whole post for you, but don't want to just add duplicates everywhere. I'd love some ID help on them.

Thanks!

The thread "Iris identification, please" in Irises forum

May I ask you to take some close up photos of the blooms showing as much detail as you can?

These are from last year. Most but not all blooms are spent this year, but I'll get some new pictures tomorrow afternoon/evening (too late now, busy in the morning)
Thanks!

I'm wondering about an iris which has taken over a growth of "Immortality" iris I had planted many years ago. The plant is a tall bearded iris with scapes 39" to 45" tall. The flowers are enormous. Falls measure 9" across, the standards are 4" tall and wide and the beards are bright yellow-gold fading to a pale lavender at their end on the falls. In indoor light a very pale lavender edge appears on the ruffled edges of the falls and standards. The flowers are very fragrant, three stems scented the whole first floor of my house. Husband says the fragrance is like a strong perfume. I would describe the fragrance as spicy or peppery. Leaves are strong green. Branches appear on each stem along with three or four buds. Rhizomes appear to be tetraploid. The petals are very sturdy, although, the photos don't appear to show that because we have had several days in a row of rain and drizzle. I hope someone will recognize this variety. Thanks in advance.

If a new iris arises de novo where another used to be, it's probably a seedling.

Looks a lot like Lacy Snowflake, which is a pretty tall Iris.. My flowers rarely reach their full potential, size-wise here.. They are of a nice size, but compete with tree roots, poor soil, etc..
Yours appears to be of a similar vintage, has laced edges, and haft markings like Lacy Snowflake...