Key for identifying the members of genus Chamaegastrodia

1. Apex of epichile contracted, with rarely entired or only slightly erose margin .................................................................................2

- Apex of epichile enlarged, partite.......................................................................................................................................................3

2. Lip canoe-shaped, margin wavy; column, with 2 triangular, fleshy wings attached to apex vertically..................... C. guidongensis

- Lip narrowly ovate to ovate-oblong, apex acute to acuminate; column with 2 dentoid norrow-lanceolate stigmatic processes attached to apex ................................................................................................................................................................. C. vaginata

3. Lip Y-shaped, with a deep incision at apex of epichile, saccate at base.............................................................................................4

- Lip T-shaped, with slightly notched epichile at apex .........................................................................................................................5

4. Lip orange yellow, ca. 16 × 13 mm, with a pair of elongate introrse lobules at the epichile lobes ................................... C. poilanei

- Lip light yellow, 11.2–12.2 × 5.8–7 mm at apex, absence of a pair of elongate introrse lobules at the epichile lobes ....................... ..................................................................................................................................................................................... C. nanlingensis

5. Lip with crisped margin at apex ........................................................................................................................................... C. asraoa

- Lip with entire margin at apex............................................................................................................................................................6

6. Lip mesochile lacking external flanges; anther with 2 narrowly triangular-lanceolate lobes at base, sessile...................... C. inverta

- Lip mesochile with external flanges; anther lacking basal lobes, attached to column via a short filament................... C. shikokiana