Nghe An Prov., Ky Son Distr., Nam Can Municipality, eastern slopes of Phu Xai Lai Leng mountain system.
Secondary broad-leaved open forest and secondary scrub on very steep clay laterite hill slopes on shale along road at elevation 650-750 m a.s.l. around point 19°13′21.9″N 104°15′04.0″E.
Riparian and subaquatic erect herb to 20 cm tall in shallow water of small stream. Flowers purple. Leaves with very strong pleasant fragrance. Occasional.
20 October 2013 CPC 6003 Coll.: L.Averyanov, N.T.Hiep, N.S.Khang, L.M.Tuan