Son La Prov., Moc Chau Distr., Chieng Son comm., about 1 km to NE from Chieng Son village, around point 20°46’02.0N 104°37’03.1E. Remnants of primary broad-leaved evergreen forest on tops of hills composed with karstic highly eroded yellow-white limestone at elevation 1100-1050 m a.s.l. Terrestrial herb to 40 cm high. In open grassy place. Flowers purple-violet. Occasional.
Son La Prov., Moc Chau Distr., Chieng Son comm., about 1 km to NE from Chieng Son Village, around point 20°46’02.0N 104°37’03.1E. Remnants of primary broad-leaved evergreen forest on tops of hills composed with karstic highly eroded yellow-white limestone at elevation 1150-1250 m a.s.l. Lithophytic uhdershrub to 1 m tall on exposed mossy rocks near mountain top. Flowers greenish with violet tint. Not common.
Ha Giang Prov., Bac Me Distr., Phieng Luong municipality, around Phieng Day village. Degraded primary broad-leaved humid evergreen forest along rocky canyon of small stream at the base of mountains composed with solid crystalline highly eroded limestone at elevation 900-1000 m a.s.l. around point 22°38’43.8’’N 105°19’19.8’’E. Shrub about 2 m tall on stream slope. Flower buds yellow. Rare.
Cao Bang Prov., Bao Lac Distr., Hong An municipality, Mi Lung village. Primary broad-leaved and mixed humid evergreen forest on very steep slopes and along rocky ridge composed with solid crystalline highly eroded limestone at elevation 1400-1450 m a.s.l. around point 22°49’23.4’’N 105°49’54.5’’E. Shrub 1.5-2 m tall. Flowers dull purple-violet, leaves dark green with violet tint. Not common.