Pachypodium gracilius

Description

Pachypodium gracilius is a species of Pachypodium endemic to Madagascar. The plant trunk is pachycaul, and typically short and fat. It produces yellow flowers. Recent revision of this taxon consider it as a subspecies of Pachypodium rosulatum: Pachypodium rosulatum subsp. gracilius Pachypodium is a genus of succulent spine-bearing trees and shrubs, native to Madagascar and Africa. It belongs to the family Apocynaceae. Pachypodium are native to Madagascar and continental Southern Africa, i.e. Angola, Zaire, Botswana, Mozambique, Namibia, South Africa, Eswatini and Zimbabwe. In elevation, Pachypodium in both mainland Africa and Madagascar grow between an altitude of sea level, where some species grow in sand dunes, such as Pachypodium geayi, to 1,600 m (5,200 ft) for Pachypodium lealii in southern Africa and 1,900 m (6,200 ft) for Pachypodium brevicaule in Madagascar. In continental southern Africa, the extreme temperatures range from −10 °C (14 °F) in some locations to as much as 45 °C (113 °F). Whereas in Madagascar, with not such a great temperature amplitude, the temperature ranges from −6 to 40 °C (21 to 104 °F). A generalization about precipitation regimes for both southern Africa and Madagascar does not have much meaning because the habitats of Pachypodium vary so greatly with a moisture regime. In some places, Pachypodium receive annually from as little as 75 mm (3.0 in) from the southern part of Africa to a high level of 1,985 mm (78.1 in). A precipitation regime for a species of Pachypodium, therefore, depends upon a habitat's location relative to the influences of the Atlantic and Indian Oceans and the various mountain ranges of southern continental Africa and of Madagascar. The genus grows in areas where there are significant periods of dry months that range from five months to ten months. It would seem likely that the Atlantic and India Oceans pay a major role in the creation of weather conducive to rainfall, not to mention mountain ranges. For example, the Madagascar dry deciduous forests with their long dry season and severe limestone ridden soils provide one ideal setting for pachypodium.