Hoa Binh Prov., Lac Son Distr., Ngoc Son Municipality, Khu Village, Khu Na Mt., around point 20°26′43”N 105°19′57”E.
Edges of heavily logged closed primary and secondary evergreen broad-leaved forest on foot and slopes of limestone mts., especially on open and wet sites along stream banks, at elevation about 530-650 m a.s.l.
Perennial herb, up to 1-1.5 m tall. Flowers white.