Photo above shows dried Adenium seedlings that I got from a friend.
Adenium can be grown from seeds or propagate from stem-cut.
Those grown from seeds have bigger caudex (the swollen trunk/stem). However, I read that even well-fertilized Adenium propagated from stem-cut can have big caudex. Very often, one will not be able to identify the difference between an Adenium grown from seed or stem-cut.
Photo above shows the Adenium grown from seed. I bought this Adenium when it was very young. After nearly 9 years, this is what I achieved. My friend said I should re-pot and uproot it more often. And regular pruning would help the caudex to grow bigger.
Photo above shows the Adenium that grew from a stem-cut. The caudex is not as big.
However, with more pruning of the stem and frequent fertilizing, its caudex may expand too.
I will try to work on growing its caudex.