This species occurs in Northern Madagascar.
Baronii is a spectacular species with its tapered shape and brilliant red flowers. The leaves form a swirl around the top of the plant and the tip of the branches which are not frequent. The conical spines are fairly short. The trunk is a light green, upright pachycaul with a swollen base that tapers to the tip. This species spectacular red flowers are formed on long peduncles in bunches. They have a white to off white center which contrasts beautifully. Baronii should be given full light and plenty of water during the warmer months for vigorous growth and plentiful flowering. Flowers will appear in early spring and last for a few weeks to a month.