| 1 | Inflorescences 3-6(10) flowered, short or clustered | 2 |
| 1 | Inflorescences 6-30 flowered, long and spike-like | 5 |
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| 2 | Leaves terete or nearly so, apices not notched | Tridactyle tridentata |
| 2 | Leaves not terete, unequally notched at the apex | 3 |
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| 3 | Leaves thick and fleshy, 10-15 mm wide; lip more or less entire | Tridactyle anthomaniaca |
| 3 | Leaves not fleshy, less than 10 mm wide; lip 3-lobed | 4 |
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| 4 | Stems up to 30 cm, pendent; leaves soft and thinly textured, linear, up to 15 cm | Tridactyle inaequilonga |
| 4 | Stems less than 15 cm, erect; leaves lanceolate, stiff and leathery, less than 6 cm | Tridactyle verrucosa |
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| 5 | Lip with lateral lobes entire | 6 |
| 5 | Lip with lateral lobes fimbriate | Tridactyle bicaudata |
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| 6 | Stem short, erect; leaves in a distinct fan, leathery, inflorescences arising at the base of the stem | Tridactyle tricuspis |
| 6 | Stem long, pendent; leaves not in a distinct fan, inflorescences spread along the stem | Tridactyle tridactylites |
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