Hello Carol. You asked what appears to be a simple qustion, and like many such, it does not have a simple answer, or, the simple answer just isn't true.But here goes. Two answers : l) probably not, and-- 2) somewhat. Just among Lycoris, for example the chromosome numbers (which are very variable) would suggest that certain species should not be compatible, but crosses have been made among some of these. Of the progeny, some appear to be fertile, others not. The cross Hippeastrum x Sprekelia would appear to be unlikely, but not only has it been made, it can be selfed , so the progeny of the cross are fertile. The only pragmatic answer at this time, is: Try the cross and see. And, try to make the reciprocal cross and back crosses if the original cross is interspecific. Keep accurate detailed records, and somewhere along the line--try to confirm the accuracy of the nomenclatural designation of the plants you're working with. A number of the Amaryllidaceae seem to be interfertile, e.g., Agapanthus species, Lycoris, and no doudbt, others witint ddesignated species, . Interspecific crosses also, may well be crossable, but there's not been much work here. I personally suspect that Hymenocallis and Narcissus might be crossable In any case, a few wild successful crosses in this area could lead to much hardier forms of what we do have. I wouldn't suggest Ixiolirion and Haemanthus together, but I can imagine Ixiolirion and Agapanthus on a trial basis. Adam in USDA Zone 5a, warming to 6 (?)