No, can't be any of those, although I am not familiar with chaenorhinum.
Incidentally, Antennaria seed is recalcitrant. I tried seed of A. rosea 'Nywood' from the NARGS seed ex probably 15 years ago a couple few times with no luck. It became a "conquer or be conquered" issue with me.
When the second round was instigated, the seed was (almost) always available and I'd always order it, as the seed is so incredibly cheap and no limit. Never any luck, until one came up this past season. Still have to grow it on to see if it is that, as I grow Gaspensis and confinis who's seeds "get away" and may have settled there and germinated.
Anyway, I did plant fresh A.r.ssp. confinis seed this year and they came up in about a month. I did save extra seed (dried) of confinis as a control to plant later. Thanks for reminding me, I still need to plant soome of them and give them a winter cold conditioning.
