Orchidantha virosa Škorničk. & Q.B.Nguyễn, sp. nov. (Lowiaceae), a new species endemic to northern Vietnam

Orchidantha virosa Škorničk. & Q.B.Nguyễn, sp. nov. (Lowiaceae), a new species from Phú Thọ province, northern Vietnam is described and illustrated here. The new species is unique among other species in Vietnam and Laos in its robust habit and size (up to 2 m) and the non-petiolate leaves in mature individuals. The key to Orchidantha N.E.Br. species of Laos and Vietnam is accordingly updated.