Rubiaceae

Ophiorrhiza sp.nov.?

Bac Kan Province, Ba Be District, Nam Mau Municipality, central part of Ba Be National Park.

Rather dray evergreen broad-leaved old secondary forest with domination of Burretiodendron hsienmu and Streblus asper on crystalline highly eroded rocky limestone at elevation 600-750 m a.s.l.

Lithophytic herb to 0.6 m tall on exposed wet rocks in humid valley between limestone hills. Leaves dark green above, dark purple brown below. Flowers white to pale pink, flower tube white with violet tint. Locally common.

16 November 2022, Nguyen Huu Cuong, Cao Xuan Hai, L. Averyanov, T. Maisak, AL 1663.