Caudiciforms

There are a variety of succulent plants, and succulent TREES.

Succulent trees are often marked by their large, swollen, trunks. The trunks store moisture for the long dry seasons.

Succulent trees are called: Caudiciforms, or among collectors, "fat plants." The large, swollen, trunks are called: Caudexes.
Here is a picture of a small adenium obesum from Africa. There are a few varieties of this plant that all flower and have similar waxy-green leaves.

Caudiciforms are extremely resilient in general, and can lie dormant, without water, for an extremely long time. I personally have a bombax ellipticum caudiciform that I did not water for two years. I only watered it two months ago, at the beginning of the summer, when it showed subtle signs of growth. Caudiciforms should be watered when they look like they are entering a growth cycle. At the sight of small leaf buds or new stems, water your caudiciform thoroughly. Here is that bombax elipticum that did not have leaves or any growth or water at all for two years: