Last year I became interested in caudiciforms and pachycauls, plants with swollen stems or trunks that serve as water-storage organs. Just take a quick look at these Google image search results to get an idea of the variety of plants that fall into these categories.
One of the most popular and most easily available caudiciform is Adenium obesum, commonly known as “desert rose.” Not only can this plant assume bizarre proportions, as seen here, it also has beautiful flowers. And one of my two desert roses has started to bloom.
The flowers are quite similar to plumeria and oleander, two related genera.
While the flower above just opened up the other day, the one below is about a week old. It’s less yellow and more pink overall. I guess it has faded in the sun, but it’s still a beautiful combination of hues. I’m glad that the flowers seem to have some staying power instead of fading quickly like cactus flowers.
The Adenium obesum above is in a 5-gallon pot. I also have a much smaller plant in a 4-inch container. While this one isn’t blooming (it’s probably still too little) it has a much fatter caudex than the larger plant above. I think over time this will become a spectacular specimen!
While Adenium obesum is native to Africa and clearly adapted to deal with little to no water, it tolerates—even loves—regular watering when actively growing. Curiously, an entire industry has sprung up in Thailand producing hybrids with ever larger and showier flowers. Just take a look at this site to see the amazing varieties that have been created.
In the fall/early winter, Adenium obesum goes dormant and should be kept dry. Some experts say no water at all until there are signs of growth in the spring, others recommend a very light watering once a month to keep the roots alive. I did the latter and my large plant still lost all its leaves while the small plant retained them.
If you’re into exotic and unusual plants, this is definitely one of the easier and more beautiful species to try!