Adenia olaboensis

Geographic & Climate

Geographic Coordinates: Central and western Madagascar (specifically recorded across Mahajanga, Toliara, and Fianarantsoa provinces, including Betioky district at Ampandrandava, north of Belo sur Tsiribihina, and Antsalova; approx. 12°S–25°S, 43°E–48°E).

Climate Classification: Tropical wet-and-dry / Savanna climate (Aw) to semi-arid steppe climate (BSh).

Habitat Characteristics: Occurs from sea level up to 1,000 meters (potentially to 1,500 meters) elevation. Found in dry secondary deciduous forests, grassy savannas, and under scrub vegetation, thriving on a diverse range of substrates including calcareous soils and sandstone outcrops.

Botanical Morphology

Diagnostic Features: Forms a large caudiciform vine featuring a swollen, conical, or bottle-shaped woody stem/base growing up to 2–4 meters tall/long. The bark surface is distinctly rugged, woody, and decorated with prominent longitudinal grooves and veins resembling crocodile skin (locally referred to as "olaboay"). Slender, climbing annual stems emerge from the massive central caudex, bearing palmate leaves typically divided into 3 lobes with softly undulating margins and clearly visible venation.

Growth Habit: Deciduous woody climber/caudiciform with a distinct seasonal dormancy. Exhibits a slow growth rate in cultivation, shedding its leaves during the dry or cooler winter season while the swollen caudex remains dormant.

History & Etymology

Etymology: The specific epithet "olaboensis" is derived from the local Malagasy name associated with the plant and its type locality or regional vernacular context.

Historical Context: First described scientifically by French botanist Paul Claverie. Long recognized by the local Sakalava people of Madagascar as "olaboay" (meaning crocodile, due to the rough, textured surface of the swollen stem), it has gained recognition among specialist caudex collectors worldwide.