Luang Prabang prov., Ngoy distr., Nong Khiew village, Pha Deng Mountain around point 20°34'14.3''N 102°37'31.8''E.
Secondary semideciduous and evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 700-825 m a.s.l. Tree 6-8 m tall among secondary shrubs. Flowers yellow. Common.
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.