Scientific Name:
Melilotus Mill., Gard. Dict., ed. 4, (1754)

Annual, biennial or short-lived perennial, procumbent to erect herbs. Lvs pinnately 3-foliolate; principal lateral veins thin and straight, terminating at leaflet margin often in a tooth; stipules adnate to petiole. Infl. axillary, racemose, slender and often lax, few- to many-flowered; bracts present subtending fls, or 0.  Calyx teeth 5, subequal, the upper longer.  Corolla deciduous after flowering.  Vexillary filament free or connate to the middle with the others; anthers uniform.  Style glabrous; stigma terminal.  Pod indehiscent or tardily 2-valved, ± straight, subglobose or ovoid, not armed, 1–2-seeded, rarely more; seeds estrophiolate, smooth and round in N.Z. spp.

[From:  Webb et al. (1988) Flora of New Zealand. Volume 4.]

Number of species in New Zealand within Melilotus Mill.
Exotic: Fully Naturalised3
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Miller, P. 1754: The Gardeners Dictionary. Vol. 2. Edition 4.