Blackseed, American, or Rugel's plantain is indeed native. It's Eurasian cousin, Plantago major, is just as common in our lawns. If the wide leaves of the plantains you're mowing have red or purple petioles, they're probably the natives. The young leaves are edible (not that you would want them). The Menominee used the leaves to make poultices for burns and inflammations. Here are plants with white anthers, which are at least as common as the purple.