Key to the determination of species in the genus Triphora in Mexico

1. Leaves with extended lamina .............................................................................................................................................................2

1’. Leaves scale-like ................................................................................................................................................................................5

2. Lip slightly three-lobed, presence of scattered subulate fleshy projections in the central lobe ............................................ T. debilis

2’. Lip conspicuously three-lobed, presence of fleshy projections of different shapes arranged in lines along the lip ..........................3

3. Flowers not resupinate, central lobe of lip rectangular ............................................................................................... T. yucatanensis

3’. Flowers resupinate, central lobe of lip suborbicular to deltoid or obovate ........................................................................................4

4. Central lobe of the lip with purple spots .......................................................................................................................... T. mexicana

4’. Central lobe of the lip without purple spots ............................................................................................................. T. trianthophoros

5. Lip with five lines with fleshy projections.................................................................................................................... T. hassleriana

5’. Lip with three lines with fleshy projections .......................................................................................................................................6

6. Lateral lobes of the lip with obtuse apex, union with central lobe not constricted ............................................................. T. wagneri

6’. Lateral lobes of the lip with acute apex, union with central lobe constricted ....................................................................................7

7. Solitary plants, flowers resupinate, margin of lateral lobes of lip entire.......................................................................... T. gallegosii

7’. Grouped plants, flowers not resupinate, margin of lateral lobes of lip erose to lacerate ............................................ T. gentianoides