FLORA OF VIETNAM Acanthaceae Hygrophila ringens (L.) R.Br. ex Spreng.
Quang Binh Prov., Tuyen Hoa Distr., Lam Hoa municipality, Hung village, around point 17°56′10”N 105°49′15”E.
Secondary open shrubs in alluvial valley between remnant limestone hills composed with highly eroded marble-like crystalline limestone at elev. about 100 m a.s.l.
Riparian herb along small strean in rather open place. Flowers white. Occasional.