Stitchwort is a member of the chickweed family, but it is even more aggressive than the common or mouse-ear varieties. This perennial spreads by long, creeping, square stems that take root and give rise to new plants. Stitchwort hugs the ground and avoids the mower. It is a particular problem in eastern Canada and the northeastern United States, but occasionally occurs on the West Coast. Leaves of stitchwort are opposite and narrow and attached directly to the stems. Tiny white flowers have five slightly notched petals. Stitchwort grows best in areas where moisture is plentiful.