A patent atturney is the final authority But as I understand it the sport is different enought to get a patent.... most sports are not stable & often revert

A sport that does not resemble the patented parent should not use the name of the parent. To me you have a new plant and can name after yourself if you like. It will probably be unstable and as long as you do not attempt to patent it, I do not see the problem. I am a gardener, not a lawyer. Al

A significantly different, stable sport or mutation of a patented plant is not considered to be of the same genotype as the parent plant, is not covered by the parent plant's plant patent, and would be independently patentable if it meet the requirements of patentability.

Thanks Brandon. So what is the definition of 'stable'? Do reversions in a patented variegated plant invalidate the patent?

A plant is described as stable (in this case) if its asexually reproduced offspring are identical to the parent plant. All plant material has the potential to mutate, and mutation does not invalidate a plant patent. However, the characteristics that make the plant patentable are not supposed to be transitory. I haven't seen this pinned down exactly, so maybe there is some wiggle room for someone with legal standing.

If you buy a plant with variegated foliage and white blooms and the new foliage is a solid green with pink blooms, the plant is unstable. Many plants require constant pruning to remove limbs that don't match the plants description. Those branches can be started as new plants but more often than not will be unstable. Several generations of stable plants would be required to be able to confirm a plant as stable. Al

...except you can't have generations with a cloned plant (which is required for patenting).

No, you can't have gnerations, but a plant that maintains it's character through successive cut + root or tissue sample and growth, or cut and graft is stable.

There's another possibiltiy you need to check for: Did you get a mis-labeled plant from the nursery? If it's a branch sport, then you know you have something new. But if it has alwyas looked different since you got it, you may have a clerical error.

Example: I ordered a bunch of swedish aspen -- 500 of them. ONE of them turned out to be white poplar. I don't mind since I didn't have a white poplar.

It is definitely a sport...there is still a small branch of the original patented variety...but 90% of the plant is not the sport.