This species is from the Lubuk Mantuk region of West Kalimantan.  It is North of the Kapaus Hulu regency.  What I learned is Lubuk Mantuk is a village located south of the capital city of Kapuas Hulu Regency, West Kalimantan Province, Indonesia. The foliage in some ways resembles U679 and comparisons have been made of the two species, however, morphologically the clones I have at least have somewhat different growth habits.  Mantuk produces more individual plants and grows more as a bush, whereas U679 tends towards a more sizeable single or double plant.  Flowers would have to be compared for a more accurate comparison though.