| 1 | Lower pitchers urceolate; lid narrow, lacking glands |
| 1' | Lower pitchers tubular to ovoid; lid orbicular, always with glands |
| 2 | Lid with 1 or 2 appendages on lower surface; axillary buds spike-like |
| 2' | Lid without appendages on lower surface; axillary buds never spike-like |
| 3 | Mouth of pitcher oblique, dorsal pitcher surface vertical |
| 3' | Mouth of pitcher hooded, dorsal pitcher surface curving forwards |
| 4 | Leaves decurrent to at least 1/2 way down internode |
| 4' | Leaves distinctly petiolate, never decurrent |
| 5 | Stem triangular; peristome more than 0.8 cm in width |
| 5' | Stem rounded; peristome less than 0.6 cm in width |
| 6 | Margin of lower leaf blades fimbriate; upper pitchers not winged |
| 6' | Margin of lower leaves never fimbriate; upper pitchers winged or not |
| 7 | Longitudinal nerves confined to outer 1/3 of leaf blade |
| 7' | Longitudinal nerves throughout blade |
| 8 | Upper pitchers widest at mouth; partial peduncles not corymbose |
| 8' | Upper pitchers narrowing to mouth; partial peduncles corymbose |
| 9 | Leaves with 2-4 pairs of longitudinal nerves, some arising from midrib |
| 9' | Leaves with 5-7 pairs of longitudinal nerves, all arising from base |
| 10 | Lid glands numerous, small (0.1-0.2 mm) |
| 10' | Lid glands very few, large (0.3-0.6 mm) |
