Leaves pinnately 3-foliolate; leaflets finely toothed; stipules fused to petiole.
Inflorescences mostly axillary racemes; peduncle usually elongating in pod and mostly longer than subtending leaf; bracts minute or absent; bracteoles absent. Calyx with 5 ± equal teeth, persistent in pod. Standard obovate-oblong; keel blunt, equal to or shorter than the wings. Stamens diadelphous; anthers uniform. Ovary with 2–8 ovules.
Pod ± globose to ovoid, indehiscent, longer than calyx; seeds usually 1 or 2, without an obvious aril.
| | Key to the species | |
| 1 | Racemes 3–12-flowered, shorter than subtending leaves; pods more or less ovoid, acute, 5–8 mm long, concentrically ridged; stipules prominently toothed | Melilotus siculus |
| Racemes 10–100-flowered, longer than subtending leaves; pods more or less globose, obtuse, 2–5 mm long, reticulate- to transversely-wrinkled; stipules more or less bristle-like and entire or broader and toothed towards base | 2 |
| 2 | Flowers 2–3 mm long; pods c. 2 mm long; stipules more or less lanceolate, dilated and toothed towards base; annual | Melilotus indicus |
| Flowers 5–7 mm long; pods 3–5 mm long; stipules bristle-like and entire; biennial
Back to 1 | 3 |
| 3 | Flowers yellow; fruiting racemes mostly 5–10 cm long | Melilotus officinalis |
| Flowers white; fruiting racemes 10–25 cm long
Back to 2 | Melilotus albus |
