Yep, definitely bloom stalks! Once the blooming is over, those plants will shrivel and die. Do the blooming ones have any offsets attached to the mother plant? You might be able to get it to produce some more offsets if you cut off the flower stalks (more plants!
). Several of us are trying it, it's this link:
The thread "Nooooo! My one and only Unicorn is going to flower!" in
Sempervivum forum
Or you could just let it bloom and go to seed, or enjoy the flowers
lovely plants in your photos!
