1 | Inflorescence composed of racemosely arranged, pedunculate spikes, aggregated into umbels and these in panicles. Calyx up to 5 mm long. Pods with a thinly woody epicarp and a parchmentlike endocarp (Subg. Minahassae) |
1' | Inflorescence composed of racemosely or ± corymbiform arranged pedunculate racemes. Calyx 7 mm long or more. Pods with a thin and flaking epicarp and a woody endocarp (Subg. Serianthes) |
2 | Calyx and corolla with yellowish brown indument. Corolla-tube usually not projecting beyond the calyx. Pod swollen over the seeds; valves with hardly branched main veins. Main vein of leaflets strongly diagonal for more than the central third of the leaflet |
2' | Calyx with rusty brown indument, darker than the corolla. Corolla-tube projecting beyond the calyx. Pod not swollen over the seeds; valves with branched main vein. Main vein of leaflets diagonal across about the central third of the leaflet |
3 | Pinnae c. 20 pairs per leaf; leaflets (10—)12—15(—16) mm long. Corolla 27-36 mm long. Pod 6-6.5 cm wide |
3' | Pinnae 6-10(-ll) pairs per leaf; leaflets (7-)9-17(-23) mm long. Corolla 24-29 mm long. Pod 4.5-6 cm wide |