Cactus / Ariocarpus elongatus

I bought seeds of ariocarpus retusus v elongatus f CDS45 and sowed seeds on 31/08/2006. I grafted young seedlings.
It is difficult to fined differences between elongatus and torigonus but I assume this is a true elongatus. Both species will have light-yellow flowers. Two plants werer in flowers and I crossed them. I can collect seeds next spring.