Phaius duongae (orchidaceae, collabieae), a new cauline species from southern vietnam

An unusual species of Phaius discovered in the Da Nang City Area in southern Vietnam is described here as new to science. It is similar to P. hekouensis but can be recognized by the smaller habit, flower color, lip ornamentation, spur, and column characters. The standard taxonomic description, as well as data on its distribution, ecology, phenology, proposed conservation status, and taxonomic notes on relationships with morphologically similar species, are presented.