Phylogeny and Taxonomic Synopsis of the Genus (Nyctaginaceae).

Comm. ex Juss. is one of the renowned genera in the Nyctaginaceae, but despite its recognized horticultural value, the taxonomy and phylogeny of the genus is not well-studied. Phylogenetic reconstructions based on plastid genomes showed that and are basal taxa, while is sister to two distinct clades: the predominantly cultivated clade (, , , cultivar, ) and the clade containing wild species of (, , , , , , and var. ). Early divergence of , and is highly supported, thus the previously proposed division of into two subgenera ( and ) was not reflected in this study. Morphological analysis also revealed that leaf arrangement, size, and indumentum together with the perianth tube and anthocarp shape and indumentum are important characteristics in differentiating the species of . In the present study, 11 species and one variety are recognized in . Six names are newly reduced to synonymy, and lectotypes are designated for 27 names. In addition, a revised identification key and illustrations of the distinguishing parts are also provided in the paper.