Taxonomy of the Nicotiana megalosiphon species complex (Solanaceae; Nicotiana section Suaveolentes): analyses of RADseq data identifies a new cryptic species

Abstract

The Nicotiana megalosiphon Van Heurck & Müll.Arg. species complex has been shown to be composed of several morphologically cryptic species similar to N. simulans N.T.Burb. Using phylogenetic and population genetic approaches (maximum likelihood, co-ancestry, admixture proportions, Bayesian species delimitation and coalescent methods), we demonstrate that there is an additional undescribed species in this complex. The species limits of N. latifolia M.W.Chase & Christenh., N. latzii M.W.Chase, R.W.Jobson & Christenh., N. megalosiphon, N. sessilifolia (P.Horton) M.W.Chase & Christenh. and N. simulans, previously circumscribed based solely on a phylogenetic approach, are confirmed in the new analyses and a new species, N. palssonae M.W.Chase & Christenh., is described. A map of species distributions and a key to the species of the N. megalosiphon species complex are provided.