Pelargonium carnosum
Unfortunately this one lasted many years but died a few month ago. It looks like if some wood borer insect made it's way inside the plant. Never happened this before to any of my pelargoniums. I think I still have 2 seeds left so I'll try to sow it again. Very attractive plant due to the swollen stem.
Pelargonium capitatum
One immediately thinks of a rose scented geranium, such as P. capitatum 'Attar of Roses'. But nature had other plans for this specimen. I bought the seeds from South Africa and they were probably from a wild P. capitatum plant. The scent was very strong and really disgusting. Nothing to do with a pleasant rose scent. All the seeds of the lot produced plants with the same horrible smell. It was a hard way to learn that the scent of P. capitatum and others varies greatly among wild plants and that the scent is irrelevant to identify a species.
P. capitatum seed pod. I always spread a bit of white glue at the tip so that seeds remain attached when ripe.