1Midrib above either not visible, hidden in a narrow groove, or rarely visible as a very slender and sharp sunken line
1'Midrib above clearly visible, but sometimes covered with hairs
2Nerves 12-30 per side. Calyx connate for ⅓. Petals not clawed. Disc annular or slightly cup-shaped. Stipe of fruit 0-6(-15) mm high
2'Nerves 6-15 per side. Calyx connate for ½-⅔. Petals clawed. Disc cup-shaped. Stipe of fruit 10-25 mm high
3Inflorescences axillary, pseudoterminal, and ramiflorous. Calyx connate for ¼. Petals 0-2. Disc not interrupted, c. 1.5 mm in diam., puberulous. Stipe of fruit 1.5-6(-15) mm high; endocarp pubescent to densely woolly
3'Inflorescences ramiflorous (rarely also axillary). Calyx connate for ⅓. Petals (|3-)5. Disc often interrupted, 0.75-1 mm in diam., glabrous or locally puberulous. Fruit not (or hardly) stipitate; endocarp glabrous
4Midrib above more or less hairy in at least some leaflets
4'Midrib above always glabrous, rarely subglabrous (see M. reticulatus)
5Petiolules 4-18(-25) mm long. Cymules stalked, short sericeous. Calyx connate lor ⅓-⅔. Petals (0) 1-5. Filaments hairy. Fruits outside glabrous
5'Petiolules 2-5 mm long. Cymules almost sessile, long-hairy. Calyx connate for ⅓. Petals absent. Filaments glabrous. Fruit outside densely ferrugineous
6Inflorescences ramiflorous (rarely also axillary).
6'Inflorescences axillary and pseudoterminal.
7Inflorescence branches more than 11 cm long, branching. Fruit without a stipe or stipe at most 3 mm high
7'Inflorescence branches less than 11 cm long, branching or not. Fruit stipe at least 4 mm high
8Fruits not stipitate or stipe at most 1 mm high. Calyx outside sparsely pubescent, inside puberulous near the base, often as a row of short hairs. Disc often irregularly deeply lobed to interrupted. Arillode without pseudo-funicle.
8'Fruit stipe 1-3 mm high. Calyx outside glabrous, inside glabrous or with a few hairs. Disc slightly lobed. Arillode with short pseudo-funicle
9Inflorescence axes up to 10 cm long, not or very sparsely branched. Calyx hardly connate. Petals (2-)5. Filaments sparsely hairy or glabrous
9'Inflorescence axes up to 5 cm long, branching. Calyx connate for ½-¾. Petals absent. Filaments glabrous
10Midrib above prominent, angular to rounded. Calyx connate for ⅓ (if connate for more than ¼, then petals absent and filaments glabrous). Petals well-developed but not clawed, or reduced to absent. Disc annular, 1—2(—3) mm in diam. Filaments hairy or glabrous
10'Midrib above a prominulous to flattened slender line only. Calyx connate for ⅓- ⅔. Petals 1-5, well developed, clawed. Disc cup-shaped, 0.5-1 mm in diam. Fila ments ± hairy
11Leaflets (1 or) 2-6 per side; midrib above angular (to locally to rarely completely rounded); reticulation usually coarse. Calyx outside ± puberulous all over, hardly connate (rarely for ¼). Petals 0-5. Filaments usually puberulous at least at the base (to glabrous); anthers glabrous or ± hairy
11'Leaflets 1-3 (or 4) per side; midrib above rounded, locally (to completely) angular; reticulation usually fine and dense. Calyx outside ± hairy in the lower half only, connate for ¼-⅓. Petals 0 (rarely up to 3 in Peninsular Malaysia). Filaments glabrous; anthers glabrous