Missouri Plants Black medick   (Medicago lupulina) Tracheophyta: Angiospermae: Dicot: Legume (Fabaceae) Non-native, from Asia Habitat: full sun waste areas. ID Features: small yellow flowers, trifoliate leaves. Natural History: Black medick is a legume and, as such, enriches soil through nitrogen fixation. It probably has no medicinal value.
The information is from: Missouri Wildflowers by Edgar Denison, 5th Edition, Missouri Department of Conservation, ©1998.