Moringa hildebrandtii

Olson, E. & Razafimandimbison, Sylvain G., 2000, Moringa hildebrandtii (Moringaceae): a tree extinct in the wild but preserved by indigenous horticultural practices in Madagascar, Adansonia (3) 22 (2), pp. 217-221 : 220

OF M. HILDEBRANDTII

Members of the genus Moringa have been found wild in dry tropical habitats in various parts of Africa and Asia, but all collections of Moringa hildebrandtii come from Madagascar, and it seems certain that the species is native there (VERDCOURT 1985, and references therein). Though clearly a distinct species based on leaf, bark, and floral characteristics (e.g. KERAUDREN- AYMONIN 1982), as well as DNA sequence data (OLSON unpubl.), Moringa hildebrandtii shares numerous features in its habit and floral morphology to the other Malagasy species M. drouhardii . Wood anatomy (O LSON & CARLQUIST in press), floral development, and DNA sequence analysis (OLSON unpubl.) suggest that the two Malagasy species are more closely related to each other than to other Moringa species, supporting the idea that they evolved from a common ancestor on Madagascar.

Ethnobotanical information suggests that the native range of Moringa hildebrandtii was the extreme southwest of the island. From 1550 to 1921, this region was the dominion of the Maroseranana, the collective name for the descendants of King Olombetsitoto ( POIRIER 1953; dark gray area in Fig. 3 ). Moringa hildebrandtii is known to members of the Sakalavan’i Menabe tribe, which now occupies most of the west coast of Madagascar, by the common name “hazomaroseranana” or “hazmaroserana” derived from “hazo”(tree) and “Maroseranana,”meaning tree of the Maroseranana family or region. We visited areas in the former Maroseranana country southeast of Tuléar, and though M. hildebrandtii is commonly cultivated, again no one knew where it could be found in the wild. Local people were however aware of the stands of Moringa drouhardii in their areas. The southeast of the island supports similar habitats, but M. hildebrandtii does not seem to be cultivated there, and we located no wild populations.

Evidence of a more circumstantial nature based on the habitat preferences of the other 12 Moringa species also points to the area south rather than north of the Onilahy River as being the most likely in which M. hildebrandtii originallyoccurred. Worldwide, all other Moringa species occur in areas with very short rainy seasons and low, open vegetation. In Madagascar, such areas occur only in the extreme southwest south of the Onilahy,the island’s driest region. The other native Malagasy Moringa species is restricted to this region and it seems likely that the original range of M. hildebrandtii was also within the area. It is reasonable to discount the eastern rainforests and central highlands as potential areas in which the tree might be found, because M. hildebrandtii , like all members of the family, is a heat-loving xerophy te.

Furthermore, no Moringa species is known from relatively tall and moist vegetation formations similar to the dry deciduous forests (sensu LOWRY et al. 1997) of western and northwest Madagascar, so it seems unlikely that M. hildebrandtii occurred there. Though the possibility remains that M. hildebrandtii still grows wild in an area not considered by us or previous authors, we recommend that searches for the tree focus on the southwest. The scope of such searches can be greatly enhanced by interviewing local people about the presence of the tree in their area. Likewise, the memory of local people could help to ascertain whether or not an apparently wild stand is in fact a relic of an abandoned settlement.

Figures

Fig. 3. — Distribution of Moringa hildebrandtii in Madagascar. M. hildebrandtii is commonly cultivated in the area delimited by a dashed line on the west coast. Previous authors have cited the light gray area between Morondava and Tulear as being the native range of the species. It is more likely the dark gray area in the extreme southwest; searches for the tree should concentrate there.