White Melilot, White Sweetclover, White Sweet-clover: Melilotus albus (Synonyms: Melilotus alba, Melilotus albus var. annuus, Melilotus officinalis var. alba) - The USDA website lumps this species in with Melilotus officinalis -
Annual Yellow Sweetclover, Annual Yellow Sweet-clover, Indian Sweet-clover, Small-flowered Yellow Sweetclover, Small-flowered Yellow Sweet-clover, Small Yellow Melilot: Melilotus indicus (Synonym: Melilotus indica) -
Common Yellow Sweetclover, Common Yellow Sweet-clover: Melilotus officinalis (Synonyms: Melilotus leucanthus, Melilotus lutea, Melilotus officinalis var. micranthus, Trifolium officinalis) -