This question comes up fairly regularly. It is discussed in several
books, and has been discussed on most Iris chat groups.
I brought it up a few times myself.
I was confused by the fact that I had plants that were supposed to be both,
but weren't really either. What I had was clearly a white I. pallida, and
it was driving me crazy for several years.
It was members of this group that helped to straighten me out on what
'Albicans' and 'Florentina' really are.
I have the "real" 'Albicans' and 'Florentina' now, and the difference is
actually very easy to see. First of all 'Albicans' flowers very early,
often right along with most of the SDB's (even before many of them).
'Florentina' is somewhat later.
'Albicans' has moderately wide leaves, and the fan looks a bit "wavy",
while the leaves of 'Florentina' are narrower and the fan is flatter.
'Albicans' usually has short branches on the flowering stalk and the flowers are
held close to the top of the ovary. The bracts are somewhat rounded and
inflated looking, and green with a sharply defined papery margin at the top
edge. They don't look blue in my garden at all, but clean white with a bit
'Florentina' comes on about a week or two later, seems to average a bit
taller, and the flower looks a bit more "slender" and "stretched out".
They are held above the bracts on a longer tube, and the bracts are more papery
when the flowers open (but still green when still in bud, and toward the base
when the flowers are open). For me the buds are light blue before the
flower opens, and the flowers have a bluish tinge. There are prominent
hairs on the narrowed base of the standards in 'Florentina' but not on those of
Of course this ignores the fact that the original 'Florentina' was probably
actually 'Albicans' and not what everyone is calling 'Florentina' now. In
the photos I've seen, the appearance is sort of in between the two.
I have not had the clone known as "I. germanica alba" flower for me yet, so
I don't know for sure how it compares with 'Albicans' and 'Florentina'.
My white I. pallida are similar, but they flower later with the TB's (and
with most other I. pallida clones), and they have entirely papery pale bracts
even when still in early bud. Right up until they open the flowers tend to
stay crumpled up inside the bracts, and don't protrude beyond the bracts in a
neat rolled up pointed bundle as in the others. They are typical I.
pallida, except that the flowers are pure white.