Doug, I can't answer properly to your question, but I have found two clones of Hippeastrum aulicum here. The one in my photo is the 'robust' one with flowers of 20cm (almost 8") across of a vivid red orange. The 'weak' one has flowers of 12cm (barely 4") of a paler colour with more green. It's not a matter of cultivation, because the 'weak' one grows well, but it is just smaller. Probably there's a bit of variability in this species. Angelo Porcelli Italy