Traditional medicinal uses, diversity, and conservation status of Malagasy aromatic plants: a review

Abstract

Background: Madagascar is a global biodiversity hotspot, with high plant endemism. Aromatic plants are crucial for traditional medicine and for economic applications, including essential oils, cosmetics, and pharmaceutical products. However,  habitat loss,  overharvesting, and  climate change threaten many species, and comprehensive nationwide assessments remain scarce. This study aims to provide an updated synthesis of the diversity, medicinal uses, and conservation status of Malagasy aromatic plants.

Methods: A literature-based review was conducted using 314 scientific and technical references, including peer-reviewed publications, books, theses, and institutional reports. Aromatic species were identified through essential-oil analyses, botanical descriptions, and herbarium records. Taxonomic and ecological information was compiled from the Catalogue of the Plants of Madagascar and conservation data from the IUCN Red List. Traditional medicinal uses were extracted from the CNARP database and quantified using citation frequency indices. Relationships among plant parts, disease categories, and bioclimatic distribution were explored using Correspondence Factor Analysis.

Results: This study documented 1,021 aromatic species across 285 genera and 68 families, on which 70.5% are endemic to Madagascar. Shrubs were dominant with a percentage of 47%. Essential oil composition has been reported for only 34.5% of species. Traditional medicinal uses were recorded for 473 species, commonly used in infectious diseases, digestive disorders, and traumatic injuries. Among the species assessed by the IUCN, nearly 68% fall within threatened categories (Critically Endangered [CR], Endangered [EN], and Vulnerable [VU]), indicating substantial conservation concern. Conclusions: Malagasy aromatic flora is highly diverse, medicinally important, and economically valuable, largely threatened. Ex situ conservation and sustainable cultivation of endemic species can reduce pressure on wild populations while supporting local and national economies. This study provides a critical foundation for integrated strategies in research, conservation, and sustainable utilization of aromatic plants, ensuring their continued contribution to traditional medicine and potential pharmacological innovation.

Conclusions: Malagasy aromatic flora is highly diverse, medicinally important, and economically valuable, largely threatened. Ex situ conservation and sustainable cultivation of endemic species can reduce pressure on wild populations while supporting local and national economies. This study provides a critical foundation for integrated strategies in research, conservation, and sustainable utilization of aromatic plants, ensuring their continued contribution to traditional medicine and potential pharmacological innovation.

Keywords: Madagascar, aromatic plants, diversity, endemism, conservation status,  medicinal uses, sustainable management