1	Shrubs
2	Leaf-blades sericeous on abaxial surface; dichasial cyme with > 40 flowers; staminate flowers: the outer pair of tepals ≤ 7.5× 5.3 mm, the inner pair of tepals ≤ 6 × 3 mm; filaments ≥ 1.5 mm long, anthers ≤ 1.5 mm long; capsules ≤ 1.5 cm long, larger wing ≤ 1.2 cm long	Begonia besleriifolia Schott
2’	Leaf-blades glabrescent to glabrous on abaxial surface; dichasial cyme with 4 to 8 flowers; staminate flowers: the outer pair of tepals ≥ 15× 15 mm, the inner pair of tepals ≥ 12 × 3 mm; filaments ≤ 1.2 mm long, anthers ≥ 2 mm long; capsules ≥ 1.8 cm long, larger wing ≥ 2 cm long	Begonia elianeae Gregório & J.A.S. Costa
1’	Climbers
3	Stipules lanceolate; leaf-blades with serrate margins; capsules ≤ 1.2 cm wide [including wings], wings equal	Begonia fruticosa A. DC.
3’	Stipules ovate; leaf-blades with entire to sparsely dentate margins; capsules ≥ 1.5 cm wide [including wings], wings unequal, one larger than the others	Begonia polygonifolia A. DC.