A new species of critically endangered edible yam endemic to northern Madagascar, Dioscorea irodensis (Dioscoreaceae) and its conservation

Abstract

SummaryMorphological character data are used to show that a distinct morphotype of Dioscorea L. from the Irodo valley (East of Sadjoavato) in Antsiranana Province of Madagascar is an undescribed species, differing in its leaf arrangement, pubescence form and male inflorescence structure from all other taxa. It is described as Dioscorea irodensis Wilkin, Rajaonah & Randriamb., illustrated and a distribution map and ecological information provided. It is known from three sites, but is likely to have been eradicated from one of them. The population that has been studied in the field contains a very low number of adult plants. Tubers have been extracted for use as food at a level that appears to be unsustainable. Thus its provisional IUCN conservation status assessment is that it is critically endangered (CR). Its vernacular name in Irodo is Bemandry.