Oh wow....
I admit I think of Bomarea and Alstroemeria as virtually the same genus - they're so closely related!
Quite possible that aurantiaca was flowering from plants at different stages, as you suggest. It formed such vast prolific colonies. When I was little and wanted to move some alstroemeria I remember digging down and to find the root... and down... and it just seemed to come to nothing! It intrigued me as a very mysterious plant under the soil.
