Low hop clover is native to Eurasia, but it has become naturalized and widespread
in North America.
Identification:Trifolium ("three-leaved") is a
large genus, and three common yellow hop clovers are compared below. Black medic,
a relative, looks closely similar to low hop clover, so this is included too.
Up to 16" (40 cm) tall, sometimes erect, sometimes growing along the ground
2-6" (5-15 cm) tall, often forming mats.
Flowers
About ¾" (1.9 cm) high. Flowers turn brown and wilt, seeds fall to the ground instead of forming a fruit
Yellow, less than ½" (1.3 cm) across; roughly spherical, with 20-40 individual flowers; flowerheads become brown with age. Upper petals of the flowers have grooves.
About ¼" (6.3 mm) yellow flowerheads, oval to spherical, 5-15 flowers per head. Flowers turn brown when seeds ripen.
Leaves
Groups of 3. Central leaf is not on a separate stem (petiole). Leaflets about ¾" (1.9 cm) long, ¼" (6.3 mm) wide.
Groups of 3, about ¾" (1.9 cm) long; with small teeth near the leaf tips. The central leaf is on a longer stem (petiole) than with other hop clovers, often notched at the top
Alternate, in groups of 3, with a larger center leaf on a short petiole (stem), often notched at the top.
Three leaves, with slightly serrated tips, center leaf on separate petiole
Stem
Often prostrate, light green or reddish green, covered with white hairs
Seeds
Black, coiled
Fruit
Seedpods are "coiled"—this is probably the most unique feature of black medic
Range/ Zones
Habitats
Prairies (black soil, clay), weedy meadows, old fields, cropland, pastures, vacant lots, landfills, cemeteries, lawns, areas along railroads and roadsides, and miscellaneous waste areas; common in low-cut lawns
ID is uncertain 
