Abstract
Bulbophyllumromklaoense (B.sect.Lemniscata) from northern Thailand is described and illustrated as a species new to science. It is most similar to B.muscarirubrum and B.triste, but differs by having inflorescences with only 4-6 reddish-brown flowers, falcate-subovate lateral sepals that are connate only in the upper half along the interior margins, petals with erose to fimbriate margins and a lip with long cilia in the distal half on the lower surface. A comparison with other similar species in the section, as well as notes on ecology, phenology, conservation assessment and a key to B.sect.Lemniscata in Thailand are also provided.