Talking about Desert Rose (Adenium obesum subsp. obesum), Baja_Costero wrote:

This comment is about the former Adenium arabicum, a wide-bottomed Arabian form of the desert rose. This form is apparently considered a synonym of the type species of Adenium obesum, according to the CoL. I don't know the details. I will use the former name here.

Adenium arabicum is a native of Yemen and Saudi Arabia, and it can be distinguished from the typical Adenium obesum based on a few features other than geography. The leaves tend to cluster at the top of stems and they are minutely pubescent. The stem is wider at the base and more bottom heavy in its general proportions.

This plant has been used in hybridization with other forms of Adenium because of its shape (vegetative characteristics). When you raise it the right way, exposing the roots, you can arrive at a fascinating, otherworldly form where the difference between stem and roots blurs in a really attractive way. This is particularly popular in southeast Asia. Really old plants can be totally spectacular, almost unreal, especially in bloom.

Like other Adeniums, this variant likes good drainage, full sun and warmth, regular water at a higher frequency during the leafy phase than during the leafless one. It does not tolerate cold but there's no problem in our zone 11 climate.

However, our climate maxes out around 90°F and my plants do not put on much stem growth until we have temperatures in the 80s for several days. Otherwise the internodes are really short, which makes for an excellent form if your goal is for a fat-bottomed plant. Expect limited stem growth in cool climates.

Talking about Desert Rose (Adenium obesum 'Premsup Yellow'), GigiPlumeria wrote:

This is a floriferous desert rose that produces clusters of 3 or more blooms on a single stem. The blooms start as light canary yellow. As the blooms get older, the color starts to turn light to darker pink with yellow undertones. It is quite a beautiful sight when this plant has canary yellow and pink blooms at the same time. This is supposed to be a Thai hybrid that has been mass produced but still is somewhat uncommon in the U.S. at this time.

Talking about Desert Rose (Adenium obesum), deepsouth wrote:

Potting media for Adenium

Mix together:

1 Part: Coconut Coir -
1 Part: Poultry Grit (chicken grit) /or Pea Gravel - (sift out fine grain silt) -
1 Part: Sand - coarse Builder's Sand, Leveling Sand, or Horticultural Sand - (sift out fine grain silt) -
1 Part: Lump Charcoal - (Break-up or crush larger pieces) - (sift out fine grain silt) -
1 Part: Lava-rock – (volcanic cinders or pumice) (crush larger pieces) - (sift out fine grain silt) -

Optional: mix with above

1 Part: Redwood Bark / Orchid (Phalaenopsis) Mix - Break-up, cut or crush larger stems & bark
1 Part: Perlite - coarse (#4 large)

Talking about Desert Rose (Adenium obesum), plantladylin wrote:

The Desert Rose is a wonderful ornamental plant with its unusual bulbous, caudex base and beautiful blooms that come in shades of red, pink, and white. In nature, Adenium obesum reaches heights of 8 to 10 feet, but smaller specimens are grown as patio container plants or indoor houseplants and they are also popular trained as bonsai. Desert Rose is drought tolerant and prefers high light, doing best in full sun situations. It is considered evergreen but will lose its leaves during severe dry periods. The sap of Adenium obesum contains toxic glycosides, and care should be taken when pruning or handling the cut stems.

Talking about Desert Rose (Adenium obesum subsp. socotranum), Baja_Costero wrote:

First big wave of "captive" socotranums released from a Southern California nursery in 2004.