You don't say what it came up in, Paul, but it looks like another Neo. Fosperior 'Perfection' to me.

It came up in the middle of what I believe to be Ae. chantinii (3 of them). It was not near any of my Neo. Fosperior 'Perfection's.

Could there have been an old chunk of rhizome from the Neo. mixed in with the Ae. rhizomes?

Seems to be the only logical answer. Do broms that do poorly attached to their mother for whatever reason tend to throw off pups earlier than normal?

I'm not sure I understand the question, Paul. Most brom pups grow much faster attached to the mother plant. An old chunk of rhizome will sometimes produce one, but it tends to be very slow and weak, since there is no mother there for it to draw energy from.

Paul, plants that have some abuse do tend to pup early. A survival mechanism I guess.