Cao Bang Prov., Bao Lac Distr., Dinh Phung municipality, Ban O village.
Primary mixed and coniferous evergreen humid forest with (Pinus sp., Pseudotsuga sinensis, Podocarpus neriifolius) on very steep slopes and on mountain tops composed by solid highly eroded limestone at elevation 1200-1300 m a.s.l. around point 22°45′24.8″N 105°46′47.9″E.
Lithophytic fern on rocky slopes and on mountain top. Very common.