On Jun 25, 2012, at 1:05 PM, "Michael Mace" <michaelcmace@gmail.com> wrote: > . > > So what happens in real life? > > --Many of the crosses that are 12 x 12 produce plants with withered anthers, > little or no pollen, and sometimes won't even set seed if pollinated from > something else. That makes them a dead end for breeding. > > --Many of the 12 x 24 crosses produce plants with abundant pollen, and they > set seed readily. > > > One more data point: a famous cross in Moraea history was speciosa x > polystachya, which is 20 x 12. It was important because M. speciosa does > not look like a traditional Moraea at all. > > Some comments: to start the info I looked at shows 12 for both polystachya and speciosa. The reference for speciosa was more recent. This illustrates one of the main issues with counts. It's rare to find a complete list of numbers in a genus all determined by the same method and by the same researchers. Most compilations are incomplete and reflect varying numbers by different researchers etc. If the group you are looking at has B chromosomes then the older reports are often even more variable. As to the other quoted parts. With the 12x12 species crosses you've done it would seem there are natural barriers in the way. Unfortunately this is very common (makes sense in the wild, but to a hybridizer this is just a stupid concept!). Your 12x24s are probably tetraploids and it would not be uncommon to have bypassed barriers in the tetraploid forms. Triploids aren't always the case in that kind of cross. Tim Chapman