FLORA OF VIETNAM Begoniaceae Begonia “arachna” sp. nov.? Cao Bang Prov., Bao Lac Distr., Hong An municipality, Mi Lung village. Primary broad-leaved and mixed humid evergreen forest (with Podocarpus, Pinus, Fokienia and Tsuga) on very steep slopes and along rocky ridge composed with solid crystalline highly eroded limestone at elevation about 1500-1550 m a.s.l. around point 22°49’15.4’’N 105°49’53’’E. Lithophytic herb on vertical mossy cliffs and boulders. Leaves emerald green, below with purple nerves. Flowers light pink, anther and style yellow, ovary purple. Very common. 21 November 2014 CPC 7568 photos Coll.: L.Averyanov, N.T.Hiep, N.S.Khang, T.Maisak, L.Osinovetz