Quang Tri Prov., Huong Hoa Distr., Huong Lap municipality around point 16°51′49”N 106°34′11”E.
Secondary broadleaved evergreen forest and secondary shrubs on shale mountain slopes at elev. about 500 m a.s.l.
Undershrub to 1.5 m tall in open grassy slope along road. Flowers purple, anthers yellow. Very common. Main co-dominant of secondary open shrub formations on degraded soils.