<<Thank you - Google finds absolutely no mention of "iris virginica forma alba" or "iris virginica f alba", which makes it kind of hard to discover its existence. Do you happen to have the year of publication and the full catalog description? Also, the AIS wiki does list 'Virginica, Alba' as a cultivar name.>>
Sticky wicket. Really need to see what Ethel thought here....
According to the 1929 AIS Check List, page 271, repeated on 1939 AIS Check List, page 359, the Iris which was listed/sold by Van Tubergen nurseries in 1925 was actually "Prob. a white form of I. versicolor."
"Virginica alba" Van Tubergen is NOT by AIS considered an "approved name," that is a valid taxon. Note that, AIS might have considered it a valid taxon if the VanT plant HAD actually been a white virginica, although I expect they'd have disapproved it anyway, because, as I said, there is more than one white virginica.
There is no note in the 29CL as to how Ethel or whoever wrote that check list entry came to the conclusion, but given the date, they were not dealing with muddles of the distant past, and the information about this plant may well have come to them informally.
<<Forma is a taxon rank under the ICBN, so wouldn't you have to validly publish the name in a scientific journal nowdays?>>
Forma are typically considered cultivars and color variants are typically of scant botanical interest on that score alone, so that the procedure for "publishing" would be to give the clone a garden name and register that name with the American Iris Society--unless it is a bulb. "Publication" would be achieved through inclusion of said garden name-- with description noting distinguishing features-- in those dated publications issued by the AIS Registrar's office, with the "author" of the name being the originator of the name, but not invariably the "orginator" of the clone.
My take on it.
Cordially,
AMW
