Thanks all for your input.
Here's the list of the seeds I planted from NARGS seed exchange.
I can't imagine it's one of them, since the sudden appearance of growth was 6+ months since planting.
Alyssoides, allysum, antennaria, anthemis, anthyllis, chaenorhinum, chimaphila, daphne, dianthus, globularia, iberis, phyteuma, salvia.
It's growing actively now (under grow lights in my garage) ... I'll just continue to monitor it to see what develops. I'll post a follow up as it continues to grow.
