Hydnophytum kajewskii (Bugainville Island, PNG)
I only offer 2 seedgrown young plants and I am not sure if I can ever offer more again!
I only had seeds a single time.
Ant-plant guru Matthew Jebb calls this "...the most elaborate tuber structure known, which must rank as one of the most elaborate and bizarre vegetative structures in the entire plant kingdom..."
For pictures, please see here and here.