I think most begonia tubers available are raised from seed and are not true specific varieties. The last few years they were open Antonellis produced the seeds and another company grew them on as tubers. I have seen named varieties in catalogs such as White Flower Farm and they are extremely expensive. I think they are vegetatively produced so they are identical clones. If you can find any called American Hybrids they are nice. Belgium tubers look old fashioned to me. Hope this helps.