If you have more than one plant in bloom, you can have spontaneous pollination. It is true that the female anthesis precedes male anthesis, but this won't stop pollen from other Anthuriums from ending up on those receptive female blooms.
If you want to be sure of a cross or selfing, you have to bag the bloom so no other pollen can get to it - otherwise, you may end up with a real mix (assuming you do have other Anthuriums in bloom at the same time as your chosen bloom is receptive).
LariAnn
