| 1 | Lower leaves with fimbriate margin |
| 1' | Lower leaves with an entire margin |
| 2 | Pitchers markedly constricted at their middle |
| 2' | Pitchers not constricted at their middle |
| 3 | Pitcher hour-glass-shaped, alabaster-white |
| 3' | Pitcher slightly constricted at middle, green with red streaks |
| 4 | Largest pitchers small, globose or subglobose, 4-9 cm tall |
| 4' | Largest pitchers large and ellipsoid to subcylindrical or narrowly cylindrical, at least 10 cm tall |
| 5 | Non-climber 30 cm tall; aerial stem inconspicuous |
| 5' | Climber or scrambler, 1 m tall or more; aerial stem at least 40 cm long |
| 6 | Lid with a basal appendage below |
| 6' | Lid lacking a basal appendage |
| 7 | Leaf apex truncate |
| 7' | Leaf apex acute |
| 8 | Lower pitcher length: breadth 1.5: 2 |
| 8' | Lower pitcher length: breadth 3-4: 1 |
| 9 | Lower surface of lid with nectar glands mostly transversely elliptic, absent from midline |
| 9' | Lower surface of lid with nectar glands either not transversely elliptic or absent from midline, or both |
| 10 | Peristome ribs 1-5 mm high; lid half as long as mouth |
| 10' | Peristome ribs 0.5 mm high; lid about as long as mouth |
| 11 | Lid retuse; nectar glands absent from midline of lower surface |
| 11' | Lid rounded; nectar glands present on midline of lower surface |
