Bulbophyllum longiflorum vs Bulbophyllum guamense

Flowers (Bulbophyllum longiflorum on left, Bulbophyllum guamense on right)

Psuedobulbs (Bulbophyllum longiflorum (left) ridged pseudobulb with wiry hairs & Bulbophyllum guamense (right) smooth psuedobulb with thin hairs)