Houphan Prov., Viengxay Distr., Khang Pa Pong village, around point 20°19'41.4''N 104°25'10.6''E. Primary and secondary broad-leaved evergreen dry forest on very steep rocky slopes of highly eroded mountains composed by solid marble-like limestone at elev. 1000-1100 m a.s.l. Shrub 1-2 m tall on rather open rocky slope and on mountain top. Flower buds whitish. Very common.
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. Shrub to 2 m tall on mossy exposed rocks. Flowers light yellowish. Occasional.
Vientiane prov., Vang Vieng distr., Patang village, around point 19°04'15.6''N 102°24'33.2''E. Secondary broad-leaved semi-deciduous dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. about 670 m a.s.l. Terrestrial undershrub to 2 m tall. Flowers white. Not rare.
Vientiane prov., Vang Vieng distr., Patang village, around point 19°04'15.6''N 102°24'33.2''E. Secondary broad-leaved semi-deciduous dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. about 670 m a.s.l. Shrub to 3 m tall. Flowers white. Very common.
Vientiane prov., Vang Vieng distr., Oa Hom village, around point 19°06'52.4''N 102°22'35.8''E. Secondary broad-leaved evergreen and semideciduous dry forest with on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 550-650 m a.s.l. Small shrub to 3 m tall on shady rocky steep slope. Flowers white. Not rare.
Vientiane prov., Kasi distr., between Pa Chao and Nam Ken villages, Pa Chao Mt., around point 19°19'50.6''N 102°21'20.5''E.
Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 1000-1100 m a.s.l. Shrub of treelet 3-4 m tall on steep open rocky slope. Flowers white. Common.
Vientiane prov., Kasi distr., between Pa Chao and Nam Ken villages, Pa Chao Mt., around point 19°19'50.6''N 102°21'20.5''E.
Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 1000-1100 m a.s.l. Shrub 2.5-3 m tall on shady rocky steep slope. Flowers white. Not rare.
Xiangkhouang Prov., Kham Distr., Huad village, Phou tat Vinh mt., around point 19°33'02.2'N 103°39'56.3'E.
Secondary broad-leaved evergreen dry forest on alluvial valley and on foothills of limestone remnant mountains at elev. 700-750 m a.s.l. Shrub 2-3 m tall in rather open place. Flowers yellow. Occasional.
Son La Prov., Van Ho Distr., Tan Xuan comm., A Lay village, around point 20°40’46.2N 104°39’49.6E. Primary evergreen broad-leaved forest on very steep rocky slopes and on mountain tops composed with red-brown sandstone at elevation about 1500 m a.s.l. Undershrub 1.5-2 m tall on steep shady slope. Flowers white. Not common.
Son La Prov., Moc Chau Distr., Chieng Son comm., Pha Luong village, Pha Luong Mountain (elevation from Pha Luong village at 930 m to Mt. peak at 1860 m a.s.l.). Open secondary scrub after fire on flat sandy Pha Luong summit composed with eroded red-brown sandstone at elevation 1800-1850 m a.s.l. around point 20°40’23.0N 104°37’52.0E. Small shrub. Calyx brown-purple.
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 reddish-pink with gree. Common.