Classification systems have evolved over time, so that cultivars of different periods were originally registered under different conditions and using different codes.

Work was started on the first Checklist in 1919, with the first abbreviated list published in 1922. Research continued through the 1920's, culminating in the 1929 AIS Checklist that included about 12,000 names – species, forms, registered cultivars, and synonyms – and attempted "to publish all that is known about Iris names that have appeared in gardening literature during the last hundred or more years".

This was an ambitious project, so it's not surprising that some of the cultivars introduced before 1920 were never registered. In 1939, another comprehensive Checklist was published, updating the 1929 book and adding another decade of registrations and introductions. The 1939 AIS Checklist is thus the earliest one available today. In it, arils were given one of four codes:

Only one special code, "PReg." was applied only to arilbreds:

Arilbreds were, however, included in a number of classification codes. The catch is that these codes indicated only height, so also applied to other cultivars that had no aril ancestry. That means it isn't possible to know from the code alone whether one of these would actually have qualified as an arilbred. It's necessary to examine its pedigree. These included:

With the 1949 AIS Checklist, AIS changed from a comprehensive to a decennial format. It covered only those iris registered and introduced after publication of the 1939 Checklist. In the 1940s, World War II curtailed aril hybridizing in Europe and arilbred hybridizers were still struggling with the sterility barrier so relatively few new cultivars were registered. The aril codes used in the 1939 Checklist remained unchanged, but the Miscellaneous Bearded code used for arilbreds was broken into two new codes:

And once again, some cultivars that were registered under other codes (such as "DB" for Dwarf Bearded, "IB" for Intermediate Bearded, or "TB" for Tall Bearded) were later classified by ASI as arilbreds. Codes did not tell the whole story, of course. An additional description, such as "oncobred" or "¼ onco", was sometimes included.

The 1959 AIS Checklist contained more information in each individual entry, so that codes became less important. The trend became to spell out terms instead of abbreviating them, so that only four codes were listed for arils and arilbreds:

One of the idiosyncrasies of the time, which we must be aware of today, was the use of the term "oncobred" to designate any cultivar known to have onco ancestry. This included some that would be considered oncogeliabreds or even tall beardeds today, as well as those we still call oncobreds.

The 1969 AIS Checklist continued the convention of narrative entries, so that codes and abbreviations became much less important. Arils and arilbreds were registered using only two basic codes:

The use of the same code for both arils and arilbreds was sometimes confusing, but additional information was often included after the abbreviated code (such as regeliocyclus, to show that a cultivar was pure aril).

The 1979 AIS Checklists added several new codes. Aril hybrids, for example, were registered using four of them:

Arilbreds were registered using two basic codes, which corresponded to their eligibility for awards:

By this time, the fertility of the C.G. White amphidiploidlike halfbreds was well known, so that an additional code was sometimes used to indicate that type:

The 1989 AIS Checklist, and the R&I Booklets of the 1990s, follow the same conventions.

© 1998-2002 by Sharon McAllister