Manihot grahamii Hook. (Euphorbiaceae), a new alien species for the Eurasian area with nomenclatural, taxonomical, morphological and ecological notes

Abstract

Manihot is a native genus of the Northern and Southern America with diversity centres in Brazil, Mexico and Guatemala. Some taxa have colonized other continents (except Europe) where they are considered aliens. During recent floristic surveys we found the genus in the Agro Pontino area (Lazio region, Central Italy, Southern Europe). This is the second record in Europe for the genus and the first of M. grahamii for the Eurasian area. At present this taxon is to be considered as naturalized alien species in Agro Pontino (and thus in Italy and Europe). To better clarify the taxonomic and nomenclatural data, the names Janipha loeflingii var. (ß) multifida (= M. grahamii) and Jatropha carthaginensis (= M. carthaginensis) were lectotypified respectively on a specimen from K and an iconography by Jacquin.