Tall melilot

Melilotus altissimus, the tall melilot or tall yellow sweet-clover, is a biennial or short-lived perennial herb in the family Fabaceae native to Europe and western Asia and widely naturalized in temperate North America, Australia, and elsewhere. Plants are erect, sparingly branched, and reach 60-150 cm in height with stout grooved stems arising from a deep taproot. Leaves are alternate and trifoliate; the three leaflets are oblong to oblong-lanceolate, 15-30 mm long and 4-12 mm wide, finely toothed throughout, glabrous above and sparsely hairy beneath, with linear-lanceolate stipules at the leaf base. The inflorescence is a slender elongate axillary raceme 5-15 cm long bearing many small bright-yellow pea-flowers, each 4-6 mm long, on short pedicels. M. altissimus is distinguished from the very similar M. officinalis by its hairy, deep-yellow keel petal of equal length to the wings and standard, and by its black, downy fruits. Flowering takes place from June to September; the dried herb gives off a characteristic sweet vanilla-like fragrance from its coumarin content. The fruit is a small ovoid one- or two-seeded pubescent legume that turns black at maturity. The species inhabits damp meadows, riverbanks, ditches, and disturbed brackish or saline ground.