Quang Binh Prov., Minh Hoa Distr., Thuong Hoa Comm., Ban On Vill., Con Moong mt. (about 1 km N on walking trail from Ban On to Thuong Hoa), 17°40′59″N, 105°57′56″E, 250-280 m.
Clustered on just abandoned slash and burn (corn plantation) shale and limestone areas, edges of heavily logged primary and secondary evergreen broad-leaved forests on foot of limestone mts. and on stream banks. Annual herb, up to 1.5 m tall. Flowers yellowish. Common.