Pachypodium brevicaule

Origin
Pachypodium brevicaule is endemic to the central highlands of Madagascar, primarily found in the regions south of Antananarivo (e.g., around Itremo). It is arguably the most famous dwarf species within the genus and is highly protected under CITES Appendix II.

Habitat
In the wild, this species thrives in acidic environments, specifically on sandstone outcrops and granite rocks. It grows at altitudes between 1,250 and 2,000 meters. The habitat is characterized by full sun exposure and a dramatic contrast between a wet growing season and a bone-dry, cool dormant season. The plants often grow in lichen-covered rock crevices, where their flattened shape helps them blend into the surrounding stones and resist high mountain winds.

Description
Pachypodium brevicaule is a deciduous pachycaul succulent renowned for its extreme "caudiciform" habit, often resembling a pile of molten lead or a weathered rock.

Caudex & Form: It is a low-growing, tuberous dwarf species that grows more horizontally than vertically. The caudex is firm, fleshy, and irregularly shaped, often becoming flattened and spreading with age. The bark is a beautiful silvery-gray, providing a natural defense against intense UV radiation.

Spines: The plant features small, paired stipular spines, but they are often less prominent than in other Pachypodium species, appearing as small conical prickles on the growth points.

Foliage: The leaves are small, ovate, and bright green with a pale midrib. They form in tight rosettes at the tips of the "humps" on the caudex during the rainy season.

Flowers: It produces exceptionally beautiful bright yellow, funnel-shaped flowers. The blooms are relatively large compared to the plant size and typically appear in late winter or early spring, often just as the new leaves emerge.

Cultivation: This is considered a challenging species for experienced collectors. It requires a strictly acidic, well-draining mineral substrate (avoiding lime/calcium). It needs maximum light to maintain its "squat" form and must be kept absolutely dry and cool (but frost-free) during dormancy to prevent rot.