One of the sections of Aril Irises is the Regelia. Depending on the authority there are about 8 species of Regelia Iris listed. All of these species have the same or similar chromosome numbers and are interfertile. In nature one can find natural hybrids where populations come close to each other. Gardeners have also crossed many of the species with each other. Both of these are termed Regelia hybrids. Regelias also cross with Oncocyclus and these are termed Regeliocyclus. Another type of cross is a Regelia or Regelia Hybrid crossed with a bearded Iris from Section Iris. These are termed Regeliabreds and are one of the types of Arilbred Irises.
-- BobPries - 2016-01-23