| 1 | Leaflets cuneate, very rarely obtuse at the base |
| 1' | Leaflets rounded or auriculate at the base |
| 2 | Leaflets sessile |
| 2' | Leaflets petiolulate, petiolules 2-10 mm |
| 3 | Leaflets obovate; midrib very excentric, 2-4 mm from the upper margin |
| 3' | Leaflets ovate-oblong or oblong, midrib not so excentric as above, more than 6 mm from the upper margin |
| 4 | Leaflets petiolulate, the petiolule 2-2.8 mm |
| 4' | Leaflets sessile (more or less sessile in M. fortuna-tironis) |
| 5 | Leaflets with the apex auminate. Hypanthium cupular, 3.5-5 mm deep, pubescent on both surfaces |
| 5' | Leaflets with the apex obtuse or emarginate. Hypanthium glabrous
|
| 6 | Leaflets with the midrib often (very) excentric, 1-6 mm from the upper margin |
| 6' | Leaflets with the midrib not excentric as above, 7.5-27 mm from the upper margin |
| 7 | Leaves 4-15-jugate |
| 7' | Leaves (1-) 2- or 3-jugate |
| 8 | Hypanthium funnel-shaped, 9-10 mm deep. Ovary sessile.. |
| 8' | Hypanthium cupular, 2-2.5 mm deep. Ovary stipitate, the stipe c. 7 mm |
| 9 | Hypanthium tube-like, 5-6 mm deep. Ovary sessile. |
| 9' | Hypanthium short-cupular, 1-1.5 mm deep. Ovary stipitate, the stipe 2-4 mm. |
| 10 | Hypanthium funnel-shaped, 5-6 mm deep. Ovary sessile |
| 10' | Hypanthium short-cupular, 1.5-2.5 mm deep. Ovary stipitate, the stipe 3-4 mm |
