Larsenianthus, a new Asian genus of Gingers (Zingiberaceae) with four species

Larsenianthus W.J.Kress & Mood, gen. nov. is described with one new combination and three new species. Larsenianthus careyanus (Benth.) W.J.Kress & Mood, comb. nov., is widespread in India and present-day Bangladesh; L. wardianus W.J.Kress, Thet Htun & Bordelon, sp. nov., is from upper Myanmar in Kachin State; L. assamensis S.Dey, Mood, & S.Choudhury, sp. nov., is restricted to Assam, India; and L. arunachalensis M.Sabu, Sanoj & T.Rajesh Kumar, sp. nov., has only been found in Arunachal Pradesh, India. A phylogenetic analysis using the plastid trnK intron and nuclear ITS DNA sequence data indicates that the four species of Larsenianthus form a monophyletic lineage that is sister to Hedychium, a geographically widespread genus of about 50 species in tribe Zingibereae of subfamily Zingiberoideae. A dichotomous key and three-locus DNA barcodes are provided as aids for the identification of the four species of Larsenianthus.