something prickly between the irises & the street? It's not only kids (although they are the destructive ones). At our iris convention in 1983 someone dug up an iris in the display beds. Joe Ghio was great about it (his plant) pointing out that the thief had good taste.
When it is a special plant I would plant it out of sight until you have enough increases so that it doesn't matter. Crossed fingers that the found rhizome will be ok when replanted. Irises are tough.
