Key to species of Geostachys in Cambodia, Laos and Vietnam

1. Inflorescence decurved; flower-bearing branches secund; flowers yellow..................................................................... G. pierreana

- Inflorescence erect; flower-bearing branches evenly distributed around the rachis; flowers white, or white with labellum and stamen spotted with dark pink to red..................................................................................................................................................2

2. Flowers plain white with no spotting (Laos)........................................................................................................................... G. sp. A

- Flowers white, labellum and stamen spotted dark pink to red ...........................................................................................................3

3. Leaf sheaths and ligules plain green; apices of bracts, bracteoles and calyx lobes prominently aristate or mucronate ...................... ............................................................................................................................................................................................ G. aristata

- Leaf sheaths spotted or reticulate with dark red, ligules dark red; apices of bracts, bracteoles and calyx lobes round or obtuse with no prominent aristae ..................................................................................................................................................... G. annamensis