Black Medick 
Flowering - February - December.
Habitat - Lawns, fields, waste ground, roadsides, railroads.
Origin - Native to Eurasia and Africa.
Other info. - This little species is a big time weed found throughout. The plant spreads easily and can form large colonies when left untouched. The small fruits of this plant turn black when ripened and look like small kidneys.
Inflorescence - Axillary pedunculate racemes. Peduncle longer then the subtending leaf and pubescent as the stem, some hairs glandular. Raceme to 1cm long, dense in flower. Each flower subtended by a single minute bract. Bract linear, -1mm long. Pedicels to -1mm long in fruit, pilose.
Flowers - Corolla yellow to 5mm long. Standard to 3mm broad, mostly glabrous, typically with apical margins revolute. Keels apically fused. Wings connate basally to keels. Anthers pale yellow to .1mm broad. Ovary green, glabrous, +1mm long, compressed. Style short, green. Calyx 5-lobed. Lobes attenuate, the longest to 1mm long, pilose externally, glabrous internally. Fruits dark brown to black when mature, reniform or cochleate, 3-4mm long, 2mm broad, compressed, sparse pilose, reticulate.