You can see why confusion reigns on this subject ! The name 'Sunseed' is given to an f1 hybrid variety of sunflower, (Helianthus Annuus 'ha') I don't know how long it's been around, but I've come across reference to someone growing it back in 1994. In the Ukraine it's an early sunflower crop. See details on the plant
here There should be more data on the Territorial Seed Company website, but for some reason their site is unobtainable.
So what the heck are Walkers up to, claiming they've spent five years helping develop 'SunSeed(TM)' oil, and registering it with a trademark? What have they done with the flower and/or the oil to be permitted to so register it. Why are they so coy about it?
I feel we must be told!