I don't grow DN, but I know the appendages on my spaceagers have always been unreliable. So the absence of a horn wouldn't begin to convince me that a variety was mislabeled.

All of my SA irises have shown appendages in varying degrees. Even those touted as flounced have had normal beards. Regular irises have had growths at the tip of beards when they weren't supposed to almost as often. Here's an example on 'In The Mist'.
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Last year 'All Aflutter had such large appendages they were breaking inside the bud as they unfurled. You can just make it out on the two lower buds in this photo.
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I hope someone can tell you if this is correctly id-ed, but I wouldn't expect appendages to match descriptions.

Brock

Doesn't always develop horns.
This has one small purple horn on one beard.

"Noble Lady" clearly shows the horn, as seen in this picture - but I think it's a lot of fuss for something pretty insignificant :) :