Vientiane Prov., Vang Vieng Distr., Nathong village, about 5 km to the W of Vang Vieng town, Tham Kang Mt., around point 18°55’51.4”N 102°23’50.6”E. Dry broad-leaved primary and secondary evergreen forest on very steep rocky slopes and on vertical cliffs of remnant highly eroded rocky limestone mountains composed by solid crystalline limestone at elevation 300-500 m. Woody vine 2-3 m long. Floral bracts green, flowers yellow-orange, tube light greenish. Common.