Adjunto para su consideración el manuscrito titulado: An amended description for Magnolia arroyoana (Magnoliaceae) and a proposal for the new Stenopetalae group . El presente trabajo ha sometido bajo la modalidad de ARTÍCULO CIENTÍFICO y declaramos que el manuscrito no ha sido publicado total o parcialmente ni ha sido sometido paralelamente a consideración en ningún otro medio impreso o electrónico.

Magnolia buenaventurensis is described from the upper Buenaventura Reserve in El Oro Province, south-west Ecuador. This species is characterised by its glabrous features, long stipular scars, obovate-elliptic leaves, 8–10 cm in diameter flowers with 8 petals, 50–53 stamens, 12–15 carpels and ellipsoid fruits. Photographs of the new species and a distribution map are provided. Relationships with other species are discussed.