Phu Tho Prov., Tan Son Distr., Xuan Son Municipality, Du village, Nhon Mountain, around mountain top, point 21°06′51”N 104°57′34”E.
Remnants of primary evergreen primary forest on very steep slopes and cliffs composed with solid highly eroded marble-like limestone at elevation about 600 m a.s.l.
Terrestrial tuberiferous herb on very steep shady rocky slope. Inflorescence leafless to 30 cm tall. Spathe light green, female flowers green, male flowers dull purple, apex of inflorescence light dull green. Not common.
HAL 12833 19 February 2009 Coll.: L.Averyanov, P.K.Loc, N.T.Vinh, L.T.Son.