Black Medick,  Medicago lupulina
Fabaceae or Pea Family

Low, creeping plant.  Leaves with three, bristle-tipped leaflets, the middle with a distinct stalk,  Tiny, yellow, irregular flowers in small clover-like clusters.  Fruits spirally curled pods, furry, green, turning black.

Alien weed of roadsides and waste places.  In Wildwood, common in the field at the south end of the Park.

The fruit cluster of this plant is distinctive.  The alien low hop clover is also low and sprawling, with yellow clover heads, and 3-parted leaves, but leaflets not bristle-tipped and the fruits are straight.