A New Combination in Pediomelum and a New Genus, Ladeania, from Western North America (Fabaceae, Psoraleeae)

Psoralidium lenuiflorum (Pursh) Rydberg, the type of Psoralidium. Rydberg, is transferred to Pediomelum Rydberg requiring a new combination, Pediomelum tenuiflorum (Pursh) A. N. Egan in tribe Psoraleeae Lowe (Fabaceae/Leguminosae). Previously published evidence on phylogenetic relationships provides a foundation for this combination, as do shared morphological traits such as persistent bracts and air elliptical fruit that falls with the calyx. A new genus, Ladeania A. N. Egan & Reveal, is described to accommodate the two remaining species previously in Psoralidium: L. juncea (Eastwood) A. N. Egan & Reveal and L. lanceolata (Pursh) A. N. Egan & Reveal, with the latter designated as the type. Ladeania is distinguished by readily deciduous bracts accompanying a calyx that does not enlarge or elongate in fruit, but flares back from the receptacle. A lectotype is designated for Psoralea floribunda Nuttall ex Torrey & A. Gray.