Forest and Kim Starr, Starr Environmental, Bugwood.org
Not to be confused with Southern brass buttons, lesser swinecress is a summer or a winter prostrate annual that grows low to the ground and is a member of the mustard family. The leaves alternate along the stems, each one with course teeth and short hairs on the tips. White flowers with small petals bloom beginning in February and last through October.
Lesser swinecress is a fast-spreading weed and found in gardens and turfgrass throughout the U.S. In fact, it's so common that it's often found in newly seeded fescue lawns. Heavy traffic and low mowing tend to spread this weed even more. Applying a pre-emergent herbicide early in the season will help to prevent this weed from taking over lawns and landscapes.