Pachypodium horombense is a species found in Madagascar and arid regions of continental Africa . It is also known as Pachypodium rosulatum v. horombense. It is the queen of the Madagascar Pachypodiums, with many people agreeing that this is the most beautiful. All parts of plant are poisonous if ingested.
The plant trunk is typically short and fat. The trunk is smooth with conical spines. Branching occurs frequently and may start from the base. The deciduous leaves are narrow, but not as long the rosulatum, stiff, dark green with a lighter middle vein and form a rosette around the tips of branches.
It produces large, bell shaped, yellow flowers. Flowers will set in the second or third year in good conditions. It blooms in small containers and never gets too big.
Hardiness zones 9-11, (4°C/40°F,-5°C/25°F) in Winter. Horombense should be given full light, warmth and plenty of water during the warmer months and considerably less water in the cool months. The Pachypodium tends to lose its leave and go dormant in Winter. Use a potting mix consisting of 2 parts sand to 1 part peat moss to 1 part loam with small gravel added for increased drainage.