| 1 | Upper surface of the leaves pubesent, more or less scaberulous; hairs usually exceeding 0.5 mm, visible with a lens | Monotes katangensis |
| 1 | Upper surface of the leaves glabrous, puberulous or minutely tomentose; hairs very short, only visible with a microscope | 2 |
| 2 | Leaves strongly discolorous, the upper surface hairy at first becoming ± glabrous, lower surface densely greyish- or whitish-tomentose | Monotes engleri |
| 2 | Leaves concolorous, glabrous on both surfaces (petioles sometimes slightly hairy) | Monotes glaber |