After talking with Christian Dietz, he informed me that most D. dielsiana in cultivation are actually D. natalensis, so I was curious if anyone had ideas as to what my plants can be classified as. I know Tamlin was researching this a while back, so I'm hoping he can shed some light on this. If you have pictures that you wish to id. feel free to add them to this thread, and maybe we can make some comparisons. I would love to see a combination of flower and seed shots along with your "Dielsiana" plant picture since Tamlin has mentioned how diagnostic the seed can be for each species.
Below are my shots of my currently labeled D. dielsiana, and I have included pics of my D. venusta "coccicaulis" flower and seed for comparison, since it's a member of the Natalensis complex.
What I currently have labeled as D. dielsiana:
As you can see, the seed looks more "round" and is a bit larger than D. capensis, but you can check the pics below to see how much larger the seeds are than D. venusta.
Here's a comparison to seed from my D. venusta "coccicaulis"