A comparison of Monstera deliciosa and M. tacanaensis, with comments on Monstera section Tornelia (Araceae)

Abstract

Monstera deliciosa, one of the most commonly cultivated aroids, is a morphologically variable species and has traditionally been considered native to southern Mexico, Guatemala, Costa Rica and Panama. We demonstrate that M. tacanaensis, which naturally occurs in those four countries and has been considered a synonym of M. deliciosa, is a closely related but different species. The natural range of M. deliciosa is restricted to southern Mexico and Guatemala. The name M. borsigiana is a synonym of M. deliciosa, representing one of its variations. The name Tornelia fragrans (another synonym of M. deliciosa) is lectotypified. A taxonomic history of Monstera section Tornelia (of which both M. deliciosa and M. tacanaensis are members) is presented; we also include M. maderaverde of Honduras in this section. Detailed descriptions and illustrations of M. deliciosa and M. tacanaensis are provided. The seeds of M. tacanaensis are extruded from the fruit at maturity, a phenomenon first reported here for the genus.