Son La Prov., Son La City, Chieng Co Municipality, around point 21°18′24”N 103°52′53”E.
Secondary evergreen dry open broad-leaved forest on very steep rocky slopes and on tops of remnant mountain composed with highly eroded marble-like solid crystalline limestone at elevation 800-900 m a.s.l.
Shrub to 3 m tall along rocky tops of ridge. Flowers light violet, median tepal with yellow center. Very common.