Black Medick, Medicago lupulina
Weed Control Options 
Life Cycle
AnnualPropagation
Producing only by seed.Stems
Stems wiry, as much as 80 cm long and lying prostrate on the ground, or much shorter and erect or spreading.Leaves
Leaves alternate (1 per node), compound with 3 small oval leaflets shallowly toothed at the tips and the central leaflet with a definite stalk (Figure 5) and the leafstalk with a pair of thick stipules at its junction with the stem.Flowers and Fruit
Flowers individually very small but grouped in dense head-like clusters, about 1 cm in diameter, on long stalks from leaf axils. Each flower is very small, yellow (Figure 3). The seedpods are black (hence the common name), slightly coiled, prominently ridged and hairy or smooth. Flowers from early spring to late autumn, dropping its seed during most of that time.Roots and Underground Structures
The root is slender but very tough and difficult to pull out or hoe off.Habitat
Black medick occurs throughout Ontario in most soil textures. A particularly common weed in lawns, it also grows in gardens, waste places, roadsides, pastures and sometimes in cultivated fields.Distinguishing Features
It is distinguished by its compound leaves having 3 oval leaflets, all with shallow teeth towards their tips but only the central one with a definite stalk (Figure 5). The small, nearly spherical clusters of yellow flowers on stalks usually longer than the leaves (Figure 3). The small clusters of black coiled seedpods produced from those flower heads.Media Items
Figure 1: Drawing of whole plant. Top
Figure 2: Cotyledon and first true leaf. Top
Figure 3: Seedling plant. Top
Figure 4: Mature plant. Top
Figure 5: Trifoliate leaf. Top
Figure 6: Small yellow flower. Top
Figure 7: Seedpod. Top